Search

Reproductive failure represents an important cause of economic loss for the equine industry. We reviewed the cases of equine abortion and stillbirth submitted to the California Animal Health and Food Safety Laboratory System, University of California–Davis from 1990 to 2022. A total of 1,774 cases were reviewed. A confirmed cause of abortion was determined in 29.2% of the cases. Abortion or stillbirth was attributed to infectious agents in 18.7% of the cases, with Streptococcus spp., equine herpesvirus 1, and Leptospira spp. being the most prevalent. Noninfectious causes of abortion were established in 10.5% of the cases, with umbilical cord torsion being the most common. In 70.8% of the cases, a definitive cause of abortion could not be established. Our study demonstrated the difficulties in establishing an etiologic diagnosis, even when following a standard diagnostic work-up. New diagnostic approaches are needed to improve the likelihood of reaching a final diagnosis in cases of equine abortion and stillbirth.

Hairy vetch (Vicia villosa) poisoning in cattle is characterized by a systemic granulomatous inflammatory response that resembles a type-IV hypersensitivity reaction. Hairy vetch toxicity has been described in cattle worldwide. The aim of this paper was to describe 10 outbreaks of hairy vetch poisoning in cattle studied at INTA EEA Salta and INTA EEA Balcarce, Argentina, from 2004 to 2019. Clinical signs included weakness, pyrexia, dermatitis, alopecia, and progressive weight loss, which leads to death over a clinical course of approximately two weeks. A total of 12 necropsies were performed and tissue samples were collected for histopathology. The main gross changes were observed in skin, lymph nodes, liver, heart, spleen and kidneys. Other tissues, such as pancreas, thyroid, and adrenal glands, were also affected. Histological lesions consisted of multifocal to diffuse granulomatous inflammation in those organs. The toxicity of hairy vetch has been described in several countries of the world. In Argentina, the use of hairy vetch as a cover crop has become common in some regions during the past years. The data suggest that hairy vetch poisoning is an important disease in cattle. More studies are needed to contribute with further information.

Pascalia glauca is a native weed and one of the most common hepatotoxic plant affecting cattle in Argentina. Although experimental P. glauca poisoning have been reported in sheep, no spontaneous cases have been reported in this species. This work describes an outbreak of intoxication after spontaneous consumption of P. glauca, affecting 20% (6/30) sheep of a commercial flock. Affected sheep were ataxic, depressive, with mucous nasal discharge, cough and abdominal breathing. During post mortem examination, liver was swollen and a diffuse enhancement of the reticular pattern (“nutmeg liver”) was visible. Histopathological examination reveals severe and extensive acute diffuse centrilobular hepatic necrosis with hemorrhage. The presence of the toxic plant, the clinical and pathological findings allows us to confirm the etiology of this outbreak.

Monensin is an ionophore antibiotic used as a feed additive and growth promoter in cattle production worldwide. The occurrence of monensin in aquatic surficial ecosystems is of concern due to its possible detrimental effects on human health and native biota. Argentina is one of the most important cattle beef producers worldwide; however, there is little knowledge on the environmental occurrence of monensin and the associated risks to aquatic biota. In this study, we developed a method for the extraction and quantification of monensin in surface water; then, we evaluated the occurrence of monensin in a stream impacted by different animal husbandry's operations, and then, we analyzed the ecological implications of monensin residues on aquatic organisms using the risk quotient (RQ) method. Sampling was carried out on August 2017 from the headwaters to the floodplain of the El Pantanoso stream, Buenos Aires province, Argentina. Monensin detection frequency was 75% (n = 20). The median level was 0.40 μg/L and the maximum concentration was 4.70 μg/L. The main input of monensin was from a cattle slaughterhouse, an activity that has not been considered before in the literature as a source of emission of veterinary pharmaceuticals into the environment. The RQ assessment showed that monensin levels could have potential negative effects on aquatic biota in the sampling site closest to the cattle slaughterhouse. The data obtained in this study shows that monensin was present in El Pantanoso surface waters at levels of high ecotoxicological risk to aquatic biota.

Neospora caninum is an apicomplexan protozoan and a major cause of abortion in cattle worldwide. In the Argentinian Humid Pampa, bovine neosporosis causes severe economic losses. Despite this, information on the genetic structure of N. caninum in this region is limited. Therefore, this study aimed to genetically characterize N. caninum isolates associated with bovine abortion in the Humid Pampa region. For this purpose, spontaneous bovine fetal tissues submitted for diagnosis to the Veterinary Diagnostic Service at INTA Balcarce during 2008-2019 were assessed by PCR, indirect fluorescent antibody test (IFAT), and histologic analysis. PCR-positive samples were tested by multilocus microsatellite genotyping (MLGs) using 9 microsatellite markers. Thirty-one different genotypes were identified from 32 samples with at least seven markers. Argentinian MLGs were grouped into two clonal clusters when analyzed using eBURST network and principal coordinate analysis. No segregation based on the year of collection, animal biotype, or geographic origin was observed. In addition, the presence of linkage disequilibrium supported the clonal propagation of Argentinian MLGs. One Argentinian subpopulation was associated with isolates from Spain, Uruguay, Brazil, and Mexico, and the other one was linked to isolates from Scotland, Spain, and Germany. These findings reveal the presence of two clonal subpopulations of N. caninum in the Humid Pampa.

The aims of this work are, firstly, to provide the geolocalization of cases of bovine abortion with definitive diagnosis and, secondly, to estimate the economic losses due to the most frequent abortifacients diagnosed agents in cattle in Buenos Aires province, Argentina. The total beef and dairy cattle population at risk of abortion is 8,358,186 and 538,076, respectively. In beef cattle, the overall risk of abortion was estimated at 4.5% for all pregnancies, where 27.9% are due to Campylobacter fetus, Neospora caninum, Leptospira spp., Brucella abortus, and bovine viral diarrhea virus with economic losses of US$ 440 per abortion, being the annual loss to the beef industry of US$ 50,144,101. In dairy cattle, there was an 8.0% risk of suffering abortion, 26.1% produced by the same abortigenic agents. The economic losses were estimated at US$ 1,415 per abortion, which equals a total loss of US$ 17,298,498 for the dairy industry in the region. The results of this study show that infectious causes are highly prevalent in Buenos Aires province, and they caused severe economic impacts in the dairy and beef industries. Furthermore, changes in temporal trends of infectious abortion occurrence were detected, probably related to the inclusion of molecular diagnostic techniques with more sensitivity or different epidemiological or husbandry conditions in the region analyzed.

Sulphur (S) dietary excess can limit productive performance and increase polioencephalomalacia (PEM) incidence in feedlot cattle (FC). Sulphur excess ingested is transformed to hydrogen sulphide (H2 S) by sulfo-reducing ruminal bacteria (SRB), being high ruminal H2 S concentration responsible for aforementioned damages. As the ruminal mechanisms involved in H2 S concentrations increase have not been elucidated, this study aimed to evaluate the ruminal environment, and the association between ruminal H2 S and dissimilatory SRB (DSRB) concentration in FC experimentally subjected to S dietary excess. Twelve crossbred steers were randomly assigned to one of two dietary S levels (6 animals per treatment): low (LS, 0.19% S) and high (HS, 0.39% S obtained by sodium sulfate inclusion at 0.86%). The study lasted 38 days, and on days 0, 22 and 38, ruminal gas samples were taken to quantify H2 S concentration, and ruminal fluid to determine total bacteria, DSRB, protozoa, volatile fatty acid and ammonia nitrogen concentration. For ruminal H2 S concentration, S dietary × sampling day interaction was significant (p

Neospora caninum is a major reproductive disease in cattle worldwide. In the Argentinian Humid Pampa, the seroprevalence, incidence of abortions, and economic losses due to neosporosis are considerably higher in dairy than in beef cattle. Despite this, we recently demonstrated that N. caninum subpopulations are indistinctly distributed in both dairy and beef production systems. The association between genotypic characteristics defined by microsatellite analysis and the virulence of the different strains-particularly with regard to the severity and extension of histological lesions-is largely unknown. Herein, we used a morphometric approach to analyze encephalic lesions in 62 bovine fetuses spontaneously infected by N. caninum. Morphometric parameters (average size of focal lesions, number of foci/cm

Purpose: The aim of this study was to describe for the first time a natural case of ovine abortion associated with Neospora caninum in a flock with reproductive losses in Argentina. Materials and Methods: The analyzed flock consisted of 256 Texel sheep, of which 134 had been mated. A single blood sample was obtained by jugular vein puncture from 220 ewes (116 adult ewes, 104 yearling ewes) and 93 lambs. Serum samples and fetal fluid were tested using the indirect fluorescence antibody test to detect antibodies against N. caninum and T. gondii. Fetal and placental tissues from aborted fetus were examined by standard gross pathology procedures and were tested using histopathology and immunohistochemistry. Moreover, DNA from fetal and placental tissues was isolated and a PCR assay to detect N. caninum, T. gondii and Chlamydia spp. was used. Results and Discussion: The pregnancy rate was 89% (119/134), the abortion rate was 8.4% (10/119) whereas the perinatal mortality rate was 15% (16/109). Out of 116 adult ewes sampled, 34.48% presented anti-N. caninum antibodies. Ten ewes had aborted, and one fetus was directly submitted to the diagnostic laboratory for further processing. Antibodies against N. caninum were detected in fetal fluid and in the aborted dam. Histopathological analysis in fetal tissues showed multifocal lymphohistiocytic glossitis, diffuse mild lymphohistiocytic endocarditis, pericarditis and focally extensive myocarditis. Severe multifocal necrotizing placentitis and diffuse mild lymphohistiocytic placentitis with the presence of lymphohistiocytic vasculitis were observed in placenta. N. caninum was immunolabeled in the placenta and fetal tongue. In addition, N. caninum DNA was detected in placenta, central neural system, lung and heart of the aborted fetus. There was no evidence of other infectious abortifacients in the aborted fetus. Conclusion: The present study described for the first time an ovine abortion caused by N. caninum in Argentina. Further investigations at a larger scale are required to establish the role of N. caninum as an important cause of reproductive losses in sheep flocks from the region., Facultad de Ciencias Veterinarias

Neospora caninum is a leading cause of abortion in cattle worldwide. The study of the immune response against N. caninum is critical to understand its epidemiology, pathogenesis, diagnosis and, ultimately, in preventing and controlling bovine neosporosis. Herein, we determined the gene expression of innate immune components endosomal RNA-sensing TLRs, BMAP28 cathelicidin, TNF-α and IL-10 and characterized the variation in both IgG ratio and avidity at delivery in N. caninum-infected heifers challenged at day 210 of gestation, colostrum and their calves. Increased BMAP28 expression was observed not only in colostrum but also in peripheral blood mononuclear cells (PBMC) and umbilical cord of calves from N. caninum-infected heifers in comparison with mock-infected control group. In addition, statistically significant decrease of TLR7 and IL-10 expression levels were observed in umbilical cord, suggesting an attempt to avoid an exacerbated immune response against the parasite. At delivery, serum and colostrum samples from infected group evidenced specific IgG anti-N. caninum. Infected heifers showed IgG1/IgG2 ratios 1 and lower avidity values before colostrum intake. Interestingly, both IgG1/IgG2 ratios and avidity values increased in seropositive calves after colostrum intake. Overall, this study provides novel information on neonatal immunity in congenitally infected calves, which is essential to understand how the immune pathways could be manipulated or immune components could be employed in order to improve protection against neosporosis.

La dictiocaulosis o bronquitis verminosa es ocasionada por Dictyocaulus viviparus, un nematode de ciclo de vida directo, y está asociada, mayormente, a brotes de enfermedad clínica en bovinos jóvenes en su primera temporada de pastoreo. El presente trabajo describe dos brotes de bronquitis verminosa que provocó la mortandad de entre el 13,6 % y el 15,7 % de dos rodeos de vacas de cría de establecimientos de la provincia de Buenos Aires, Argentina. En ambos brotes, los hallazgos clínicopatológicos en los animales afectados y la presencia de nematodes pulmonares, en algunos casos solo observados en el estudio histopatológico, permitieron confirmar este diagnóstico., Dictyocaulosis or parasitic bronchitis is caused by Dictyocaulus viviparus, a direct life cycle nematode, and is most frequently associated with clinical disease in young cattle during their first grazing season. This work describes two outbreaks of dictyocaulosis, in two cowcalf farms in Buenos Aires province, Argentina that caused the death of 13.6 % and 15.7 % of animals, respectively. In both outbreaks, clinical and pathological findings, and the presence of nematodes in respiratory tract, in some cases only observed in the histopathological analysis, allowed diagnosis confirmation., Facultad de Ciencias Veterinarias

A pesar de su importancia, el diagnóstico etiológico del aborto en bovinos representa un desafío técnico para los veterinarios clínicos y laboratoristas, en parte debido a la dificultad de recuperar los fetos abortados en condiciones extensivas de campo. Dicha dificultad limita la posibilidad de detectar tempranamente los vientres abortados y de efectuar la investigación patológica y microbiológica de los abortos. Neospora caninum es un protozoario cosmopolita identificado como uno de los principales agentes abortigénicos en bovinos. En este estudio proponemos una aproximación seroepidemiológica para diagnosticar abortos por N. caninum en bovinos lecheros usando kits de ELISA comerciales. Se procesaron muestras de entre 12 y 93 vacas y/o vaquillonas con (casos) y sin (controles) historia reciente de aborto en 4 tambos comerciales de Uruguay. La proporción controles:casos analizados varió entre 1:1 y 4,6:1. Las muestras (n=230) fueron analizadas mediante 3 kits comerciales para la detección de anticuerpos IgG anti-N. caninum. En los 4 tambos la proporción de vacas y/o vaquillonas seropositivas por cualquier kit fue significativamente mayor en los casos respecto de los controles (odds ratio=5,13 a 36; p=0,0002 a 0,0485). La concordancia entre los kits varió de débil a fuerte (coeficiente Kappa de Cohen=0,58 a 0,83). Concluimos que, a pesar de la imperfecta concordancia entre estos kits, el empleo de todos ellos permitió arribar a conclusiones similares respecto de la asociación estadísticamente significativa entre seropositividad a N. caninum y aborto, lo que demuestra la utilidad de estos kits para la aproximación diagnóstica del aborto a nivel poblacional en condiciones de campo. Bovine abortion causes considerable economic losses to the livestock industry worldwide and is of concern for public health and food safety, given that many abortigenic infectious agents of cattle are zoonotic. Despite its importance, the etiological diagnosis of abortion in cattle is challenging both for veterinary practitioners and laboratory technicians, partly due to the difficulty in recovering aborted fetuses under extensive field conditions for pathological and microbiological diagnostic investigation, and in the early identification of aborted dams. Neospora caninum is a cosmopolitan protozoon identified as one of the main abortigenic agents in cattle worldwide. In this study we propose a comparative seroepidemiological approach for the diagnosis of abortion by N. caninum in dairy cattle. Samples from 12 to 93 cows/heifers with and without recent history of abortion (cases and controls) in four commercial dairy farms were tested. The ratio of controls to cases tested varied from 1:1 to 4.6:1. All samples (n=230) were analyzed by three commercial ELISA kits for the detection of anti-N. caninum antibodies. In all four dairy farms, the proportion of seropositive cows and/or heifers per kit was significantly higher in the cases than in the controls (Odds Ratios=5.13 to 36, p=0.0002 to 0.0485). The agreement among the three kits varied from weak to strong (Coheńs kappa coefficients=0.58 to 0.83). We conclude that, despite the imperfect agreement between these kits, all of them allowed to arrive at similar conclusions regarding the statistical association between N. caninum seropositivity and abortion, thus representing a useful tool for the diagnostic approach at the population level under field conditions. EEA Balcarce Fil: da Silva Silveira, Caroline. Instituto Nacional de Investigación Agropecuaria. Estación Experimental La Estanzuela; Uruguay. Fil: Armendano, Joaquín Ignacio. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina. Fil: Moore, Dadín Prando. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fil: Cantón, Germán José. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina. Fil: Macías Riosecoa, Melissa. Instituto Nacional de Investigación Agropecuaria. Estación Experimental La Estanzuela; Uruguay. Fil: Riet Correa, Franklin. Instituto Nacional de Investigación Agropecuaria. Estación Experimental La Estanzuela; Uruguay. Fil: Giannitti, Federico. Instituto Nacional de Investigación Agropecuaria. Estación Experimental La Estanzuela; Uruguay.

Detection of bovine viral diarrhea virus (BVDV) in aborted fetus samples is often difficult due to tissue autolysis and inappropriate sampling. Studies assessing different methods for BVDV identification in fetal specimens are scarce. The present study evaluated the agreement between different diagnostic techniques to detect BVDV infections in specimens from a large number of bovine aborted fetuses and neonatal deaths over a period of 22 years. Additionally, genetic, serological, and pathological analyses were conducted in order to characterize BVDV strains of fetal origin. Samples from 95 selected cases from 1997 to 2018 were analyzed by antigen-capture ELISA (AgELISA), nested RT-PCR (RT-nPCR), and real-time RT-PCR (RT-qPCR). In addition, amplification and sequencing of the 5′UTR region were performed for phylogenetic purposes. Virus neutralization tests against the BVDV-1a, BVDV-1b, and BVDV-2b subtypes were conducted on 60 fetal fluids of the selected cases. Furthermore, the frequency and severity of histopathological lesions were evaluated in BVDV-positive cases. This study demonstrated that RT-nPCR and RT-qPCR were more suitable than AgELISA for BVDV detection in fetal specimens. However, the agreement between the two RT-PCR methods was moderate. The BVDV-1b subtype was more frequently detected than the BVDV-1a and BVDV-2b subtypes. Neutralizing antibodies to any of the three subtypes evaluated were present in 94% of the fetal fluids. Microscopically, half of the BVDV-positive cases showed a mild non-suppurative inflammatory response. These results emphasize the need to consider different methods for a diagnostic approach of BVDV associated to reproductive losses. Fil: Spetter Lucas, Maximiliano Joaquín. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible - Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible; Argentina Fil: Louge Uriarte, Enrique Leopoldo. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Área de Investigación en Producción y Sanidad Animal; Argentina Fil: Armendano, Joaquín Ignacio. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias. Departamento de Fisiopatología. Área de Nutrición; Argentina Fil: Morrell, Eleonora Lidia. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Área de Investigación en Producción y Sanidad Animal; Argentina Fil: Cantón, Germán J.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Área de Investigación en Producción y Sanidad Animal; Argentina Fil: Verna, Andrea Elizabeth. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Área de Investigación en Producción y Sanidad Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible - Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible; Argentina Fil: Dorsch, Matías A.. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina Fil: Pereyra, Susana Beatriz. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Área de Investigación en Producción y Sanidad Animal; Argentina Fil: Odeón, Anselmo C.. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina Fil: Saliki, Jeremiah T.. University of Georgia; Estados Unidos Fil: González Altamiranda, Erika A.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible - Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

The aim of this study is to report an episode of reproductive losses due to toxoplasmosis in a sheep flock in Argentina. A total of 15 abortions and 9 stillbirths were recorded in a flock of 190 Texel ewes. The affected ewes were more likely to be seropositive for Toxoplasma gondii (15/24) than ewes that delivered normal lambs (5/34, OR = 9.6, 95%CI = 2.7–34.0, p = 0.0004). A pair of aborted twins was recovered for diagnostic investigation. One of these fetuses and its dam were seropositive for T. gondii. Histological examination of the two fetuses revealed non-suppurative myocarditis and epicarditis, portal hepatitis and multifocal necrotizing encephalitis with protozoal cysts in the brain. T. gondii was detected intralesionally by immunohistochemistry in one fetus and by PCR in both. Further investigations are necessary to evaluate the economic losses due to T. gondii in the Argentinean ovine industry.

Bacterial, protozoal and viral diseases are major causes of abortion in sheep and goats. These agents cause significant economic losses, and many are considered of concern for public health (zoonotic pathogens) and/or the international trade of livestock, such as those causing diseases notifiable to the World Organization of Animal Health (OIE). In South America, information about their occurrence, prevalence and economic impact is scarce. We review the available literature on bacterial, protozoal and viral abortifacients identified through laboratory testing in sheep and goats in South America and discuss whether the diagnostic investigations are conclusive in demonstrating abortion causality. We also compile information on diagnostic methods recommended by the OIE for the laboratory diagnosis of these abortifacients and on salient fetoplacental lesions induced by them. Campylobacteriosis (Campylobacter fetus subsp. fetus), listeriosis (Listeria ivanovii), chlamydiosis (Chlamydia abortus), toxoplasmosis, neosporosis and sarcocystiosis have been confirmed as small ruminant abortifacients in this region. Brucella ovis, Brucella melitensis, Campylobacter jejuni, Chlamydia pecorum, Coxiella burnetii, Leptospira spp., Bacillus licheniformis and bluetongue virus, are probable causes of abortion in the region since they have been detected in aborted fetuses and/or associated with abortions through seroepidemiologic studies. Listeria monocytogenes, Histophilus ovis, Actinobacillus seminis, Trueperella pyogenes, Yersinia spp., Trypanosoma vivax, caprine herpesvirus 1 and pestiviruses also infect small ruminants in the region and could thus be considered possible causes of abortion, although they have not been associated with abortion in South America (i.e., not detected in aborted fetuses nor associated with abortion through seroepidemiologic studies). Other agents such as Flexispira rappini, Francisella tularensis, Anaplasma phagocytophilum, Rift Valley fever virus, Wesselbron disease virus and bunyaviruses, known to be abortifacients for sheep and goats in other regions of the world, have not been documented in South America. While some of these agents could be exotic in this subcontinent, others may have been undiagnosed considering the limitations of active animal disease surveillance systems, which hamper the eventual detection of emerging, re-emerging, and communicable diseases in South America. Instituto Nacional de Investigación Agropecuaria Agencia Nacional de Investigación e Innovación

The aim of this study was to describe the prevalence of Neospora caninum based on the detection of specific antibodies in bulk tank milk (BTM) from dairy cattle farms in the Mar y Sierras Basin by using an enzyme-linked immunosorbent assay (ELISA). A total of 98 BTM samples from 49 dairy farms were collected during autumn and spring of 2019. Additionally, 147 paired individual milk and serum samples were collected from two dairy farms to assess the prevalence within-herd by ELISA and indirect fluorescent antibody test (IFAT, serum samples). Additionally, 12 individual serum samples were also assessed to test the agreement between IFAT and ELISA (total serum samples 159). Noteworthy, 100 and 91.84% of 49 dairy farms were positive in the BTM in autumn and spring, respectively. For the within-herd individual samples, a good agreement between serum and milk results was obtained for ELISA and IFAT (0.86–0.90). This is the first study in Argentina in which milk samples were tested to determine the N. caninum infection status at herd and within-herd levels in dairy farms, providing a base for further research.

Solanum glaucophyllum, a toxic plant known for its calcinogenic effects, causes enzootic calcinosis in ruminant and monogastric animals. We describe an outbreak of enzootic calcinosis that occurred in a herd of 110 horses grazing pastureland heavily contaminated with S. glaucophyllum in Buenos Aires province, Argentina. Ten horses developed clinical signs, and 6 horses died. Clinical signs included abnormal gait (stiff-legged action, short strides), stiffness, thoracolumbar kyphosis, reluctance to move, wide stance, chronic weight loss, weakness, recumbency, and difficulty standing. Autopsy of 2 horses revealed severe mineralization of the aorta, pulmonary arteries, heart, and lungs, consistent with enzootic calcinosis. Although horses usually have very selective grazing behavior, under food restriction conditions, they can ingest the toxic plants and can develop the disease. Enzootic calcinosis should be considered as a differential diagnosis in horses grazing S. glaucophyllum–invaded pasturelands with compatible clinical signs and lesions., Facultad de Ciencias Veterinarias

The aim of the present study was to investigate the occurrence of N. caninum associated with abortions of dairy cattle from Santa Catarina state, southern Brazil by using enzyme-linked immunosorbent assay (ELISA), immunohistochemistry (IHC), and polymerase chain reaction (PCR). Blood from dairy cows that aborted along with intrathoracic fluid and tissue samples (brain, heart, liver, and lung) from their fetuses were collected and used for serology; PCR, histopathological, and immunohistochemistry (IHC) evaluations were also conducted. Twenty-one cows (51.2%) out of 41, and eight fetuses (26.7%) out of 30 were ELISA (HerdCheck, IDEXX) positive for N. caninum. Dams > 36 months of age had a higher risk of being serum positive than younger animals. PCR and IHC revealed that 38.8% (14/36) and 25.0% (9/36) of the fetuses were positive for N. caninum, respectively for each of the tests. Seropositive cows had a higher frequency of fetuses that were also positive by either intrathoracic fluid, PCR, or IHC. In summary, the present study observed a high frequency of N. caninum in abortions from dairy cows from southern Brazil, with a higher N. caninum prevalence found in cows that were older than 36 months. In addition, serology, PCR, and IHC should be used all together for better diagnosis of neosporosis in cattle. Resumo O objetivo deste estudo foi avaliar a ocorrência de N. caninum associado a abortamentos em vacas de leite do estado de Santa Catarina, sul do Brasil pelo uso das técnicas de ELISA (HerdCheck, IDEXX), reação em cadeia pela polimerase (PCR) e imunohistoquímica (IHC). O sangue das vacas leiteiras que abortaram, bem como, o líquido intratorácico e amostras de tecidos (cérebro, coração, fígado e pulmão) de seus fetos foram coletados e usados para sorologia, PCR (Np21+ e Np6+), e IHC. Vinte e uma vacas (51,2%) de um total de 41, bem como, oito fetos (26,7%) de um total de 30 foram positivos no ELISA (IDEXX) para N. caninum. As vacas > 36 meses de idade tiveram um maior risco de serem soropositivas do que os animais mais jovens. PCR e IHC revelaram que 38,8% e 25,0% dos fetos foram positivos para N. caninum, respectivamente para cada um dos testes. As vacas soropositivas tiveram uma maior frequência de fetos que também foram positivos no fluído intratorácico, na PCR ou na IHC. Em resumo, o presente estudo observou uma alta frequência de N. caninum em abortos de vacas leiteiras na região estudada, com maior prevalência de N. caninum em vacas com mais de 36 meses de idade. Além disso, sorologia, PCR e IHC deveriam ser utilizadas conjuntamente para melhor diagnóstico de neosporose em bovinos.

Rhabdomyolysis is a myopathy characterized by severe acute myonecrosis with lysis of muscle cells and extravasation of its content into the bloodstream, causing a secondary renal failure and myoglobinuria. Case-reports have been documented in a wide range of wild or domestic animal species, but to our knowledge, no reports in water buffaloes (Bubalus bubalis) have been done. Three animals had signs of paralysis, muscle tremors and myoglobinuria while others died spontaneously. Samples of blood from affected animals showed increased levels of creatin kinase (CK), potassium (K), aspartate transaminase (AST), and lactate dehydrogenase (LDH). In addition, Selenium (Se) levels of those animals were low. Necropsy findings consisted of severe gelatinous and yellowish edema and pallor of the skeletal muscles of the hind limbs, lumbar, cervical and scapular region. Microscopically, acute and severe segmental monophasic coagulative necrosis of skeletal muscles and acute pigmentary tubular nephrosis was observed. We suspect that selenium deficiency was a predisposing factor of rhabdomyolysis in this particular case. EEA Balcarce Fil: Llada, Ignacio. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina Fil: Gianechini, Leonor S. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina Fil: Odriozola, Ernesto Raul. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina Fil: Brambilla, Emilio. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina Fil: Fernández, Eduardo.Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina Fil: Scioli, Maria Valeria. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina Fil: Canton, German Jose. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina Fil: Morrell, Eleonora. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina

In November 2015, an abortion outbreak occurred in a commercial dairy herd of 650 Holstein cows in Florida department, Uruguay. Forty-five (45) cows aborted within 3 wk. Five fetuses were subjected to gross and microscopic pathologic examination, and microbiological testing. One fetus had fibrinous epicarditis and peritonitis, and neutrophilic bronchopneumonia. Campylobacter fetus subsp. venerealis was detected by direct immunofluorescence, isolated and identified by PCR and sequencing of the 16S rDNA in the abomasal fluid and/or lung. Histologic examination of two other fetuses revealed nonsuppurative necrotizing encephalitis, lymphohistiocytic myositis and myocarditis, and lymphocytic interstitial nephritis. In these fetuses, N. caninum antigen was detected intralesionally by immunohistochemistry, and N. caninum DNA was amplified by PCR on formalin-fixed paraffin-embedded brain. Antibodies against N. caninum were detected by indirect immunofluorescence in 10 of 27 cows, with titers ranging from 1/200 to 1/3200. The results indicate that two abortigenic microorganisms may coexist and cause contemporaneous abortion in a herd. It is relevant to highlight the importance of performing multiple diagnostic tests in various aborted dams and fetuses from the same herd for the etiologic confirmation of bovine abortion syndrome En noviembre de 2015 ocurrió un brote de abortos en un hato lechero comercial de 650 vacas Holstein en el departamento de Florida, Uruguay. Cuarenta y cinco (45) vacas abortaron en un lapso de 3 semanas. Cinco fetos fueron sometidos a un examen patológico macro y microscópico y a pruebas microbiológicas. Un feto tenía epicarditis fibrinosa y peritonitis, así como bronconeumonía neutrofílica. Se detectó Campylobacter fetus subesp. venerealis utilizando inmunofluorescencia directa; se lo aisló e identificó mediante PCR y secuenciación del 16S rDNA en el líquido abomasal y en el pulmón. El examen histológico de otros dos fetos reveló encefalitis necrotizante no supurativa, miositis linfohistiocítica y miocarditis, y nefritis linfocítica intersticial. En estos fetos se detectó intralesionalmente el antígeno de N. caninum mediante análisis inmunohistoquímico, y se amplificó el ADN de N. caninum mediante PCR en tejido cerebral fijado con formalina y embebido en parafina. Se detectaron anticuerpos contra N. caninum mediante inmunofluorescencia indirecta en 10 de 27 vacas, con títulos de entre 1/200 y 1/3200. Los resultados indican que dos microorganismos abortígenos pueden coexistir y provocar abortos contemporáneos en un hato. Subrayamos la importancia de realizar pruebas diagnósticas múltiples en diversas madres abortadas y fetos del mismo hato para obtener una confirmación etiológica del síndrome de aborto bovino. EEA Balcarce Fil: Macías-Rioseco, Melissa. Instituto Nacional de Investigación Agropecuaria; Uruguay Fil: Caffarena, Rubén D. Instituto Nacional de Investigación Agropecuaria; Uruguay. Universidad de la República, Facultad de Veterinaria; Uruguay Fil: Fraga, Martín. Instituto Nacional de Investigación Agropecuaria; Uruguay Fil: Silveira, Caroline. Instituto Nacional de Investigación Agropecuaria; Uruguay Fil: Giannitti, Federico. Instituto Nacional de Investigación Agropecuaria; Uruguay. University of Minnesota, Veterinary Population Medicine Departament; Usa Fil: Cantón, Germán. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina Fil: Hecker, Yanina. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Argentina Fil: Suanes, Alejandra. Ministerio de Ganadería Agricultura y Pesca. Montevideo. Dirección de Laboratorios Veterinarios; Uruguay. Fil: Riet-Correa, Franklin. Instituto Nacional de Investigación Agropecuaria; Uruguay

Polioencefalomacia (PEM) es un término patológico que se refiere a la necrosis cerebro-cortical. En bovinos las causas más frecuentes son déficit de fibra (acidosis ruminal), déficit de tiamina y exceso de azufre (S) dietéticos. El objetivo de este trabajo es reportar un brote de PEM en bovinos de engorde a corral consumiendo exceso de S. El establecimiento afectado habitualmente suministraba una dieta de terminación compuesta por 45% de burlanda de maíz, pero 25 días antes del problema se incrementó su inclusión al 70%. Se realizó la anamnesis, exámenes clínicos individuales y poblacionales, una necropsia y la recolección de muestras de agua de bebida y alimento balaceado. Se recomendó tratar con tiamina a los animales afectados, con respuesta favorable en la mayoría de los casos. En el exámen patológico de cerebro se observó edema y hemorragias, con necrosis cortical severa. El cultivo bacteriológico de encéfalo resultó negativo. El agua de bebida contenía 1 g/l de sulfatos y el alimento balaceado 0.48% de S, de modo que el consumo estimado de S total fue de 0.58%. El exceso dietético de S podría haber estado implicado en el desarrollo de este brote de PEM, siendo éste el primer reporte en Argentina. Polioencephalomacia (PEM) refers to cerebrocortical necrosis. In bovine the most frequent causes of PEM aredietary fiber deficit, thiamine deficiency and excess of sulfur (S). The objective of this work is to report an outbreak of PEM in feedlot cattle consuming S excess. The affected farm provided a finishing diet composed of 45% corn destillers grains with solubles, but 25 days before of the problem the inclusion of this component was increased in the diet (up to 70%). Clinical and epidemiological data were collected and the autopsy of a dead animal was performed for pathological and bacteriological studies. Additionally, drinking water and balanced meal samples were carried out. Affected animals were treated with thiamine, with a favorable response. In the pathological examination of the brain, edema and hemorrhages were observed, withsevere cortical necrosis. The bacteriological culture of encephalon was negative. The drinking water contained 1 g / l of sulphates and the food 0.48% of S, so that the total estimated consumption of S was 0.58%. Dietary S excess could have favored the occurrence of this PEM outbreak. To the best of our knowledge, this is the first etiological description of S dietary excess associated with PEM in Argentina. EEA Balcarce Fil: Castro, Damian Jesus Nahuel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Marcos Juárez; Argentina Fil: Canton, German Jose. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina Fil: Margineda, Carlos Augusto. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Marcos Juárez; Argentina

The aim of this study was to describe bovine neosporosis in dairy cattle from the Sierra region, Ecuador. A case-control study was performed on 841 dairy cattle from 5 dairy herds. The overall seroprevalence was 23.4% having significant association between abortion and seropositivity (p

The aim of the present study was to characterize the specific immune response in prepubertal female calves inoculated with Neospora caninum. Forty-eight N. caninum-seronegative 6-month-old Angus female calves were randomly allocated into two groups: group A calves were inoculated subcutaneously (sc) with 1 × 106 tachyzoites of the low virulence NC-Argentina LP1 isolate in sterile phosphate-buffered saline (PBS); group B calves were mock inoculated sc with sterile PBS. Calves from group A developed a specific immune response characterized by the production of IgG antibodies and the expression of IFN-γ and TNF-α cytokines. Animals did not present any febrile reaction or reactions at the site of inoculation. Although chronic N. caninum infection was developed in 50% of calves of group A after inoculation, according to the presence of antibodies against rNc-SAG4, antigen characteristic of bradyzoites, N. caninum antibodies dropped below the cut-off of ELISA from day 210 post-inoculation onwards. Future trials using the same group of inoculated animals will allow the characterization of the evolution of the immune response during pregnancy and to determine whether the immunization with the local isolate is able to prevent congenital transmission and to protect against heterologous challenges., Facultad de Ciencias Veterinarias

Previous work carried out to characterise different immune cells in ruminant placentas found strong CD79

An outbreak of systemic granulomatous disease of unknown etiology was diagnosed in a dairy herd from Argentina. Eleven out of 211 cows manifested hyperthermia, depression, alopecia, pruritus, decreased milk production and death in most cases. During necropsy, multifocal petechial hemorrhages in glottis and vulva, white multifocal nodules in the liver and splenomegaly with subcapsular petechial hemorrhages were observed. Both kidneys were diffuse pale and enlarged. Systemic granulomatous hepatitis, myocarditis, pancreatitis and nephritis were observed. Water and food samples tested negative for Arsenic and T2 toxin, respectively. Fusarium equiseti was isolated from alfalfa hay samples. Vicia spp. was not consumed by the affected herd and no other cause of vetch-like disease was registered. Other causes of granulomatous lesions (Mycobacterium spp. and fungal infections) were discarded. The systemic granulomatous disease was suggestive of a type IV hypersensitivity reaction. Although the sensitizing agent was not determined, two components of the ration were suspected: cotton seed and bone ash. Both of them were introduced one month prior to the detection of the first affected cow and the disease resolved since they were removed from the diet. EEA Balcarce Fil: Odriozola, Ernesto Raul. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina. Fil: Dorsch, Matías. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina. Fil: Caffarena, Rubén Darío. Instituto Nacional de Investigación Agropecuaria (INIA). Plataforma de Investigación en Salud Animal. Universidad de la República. Facultad de Veterinaria; Uruguay. Fil: Moreira, Ana Rita. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina. Fil: Fernández, Eduardo Luján. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina. Fil: Morrell, Eleonora Lidia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina. Fil: Cantón, Germán José. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.

Toxoplasma gondii has a worldwide distribution and can infect almost all warm blooded animals including pigs and humans. This study aims to examine the immune responses induced in pigs following vaccination (live S48 tachyzoites) and/or challenge with T. gondii oocysts, through the examination of changes in levels of transcription in CD4, CD8α, IFN-γ, IL-12p35, CXCR3, MyD88. The experiment involved four groups of animals; pigs in group 1 (Challenged) (Chal) were challenged orally with (1 × 103 oocysts) on day 28 of the experiment. Pigs in group 2 (Vaccinated /Challenged) (Vac/Chal) were vaccinated (S48 isolate tachyzoites) on day 0, then challenged on day 28. The group 3 (Vaccinated) (Vac) animals were vaccinated (S48 isolate tachyzoites) on day 0 of the experiment. Finally the group 4 (control) pigs remained non-vaccinated and non-challenged. All animals were culled 6 weeks post challenge. At post mortem samples of retropharyngeal lymph node (RLN), mesenteric LN (MLN) and spleen were collected, RNA was extracted and cDNA synthesised. The results showed significant increases in IFN-γ expression in samples from groups 1 (Chal) and 2 (Vac/Chal) (RLN) and groups 1, 2 and 3 (Vac) (spleen) and in MyD88 expression (RLN) in samples from groups 1, 2 and 3 compared to the group 4 (control) animals. Significant increases were also observed in CD8α expression in group 1 (Chal) (RLN) and groups 1 and 2 (Vac/Chal) (RLN and MLN) compared against group 4 (control) and group 3 (Vac) respectively. Conversely, significant down regulation of CD4 and/or IL-12p35 transcription was found in at least one sample from groups 1 (Chal), 2 (Vac/Chal) and 3 (Vac) compared to group 4 (control) pigs. This study demonstrates that cell mediated and innate immune responses are generated in pigs following exposure to T. gondii parasites (oocysts or tachyzoites), key amongst them appear to be IFN-γ, MyD88 and CD8α., The authors would like to thank Scottish Government's Rural and Environment Science and Analytical Services Division (RESAS) for supporting this work and all of the members of the clinical department at the Moredun Research Institute who assisted with the experiment. This project was partially funded by a transnational access project funded through the European Union Seventh Framework Network of Animal Disease Infectiology Research Facilities (NADIR; reference number FP7-228394)

Bovine abortion is an important cause of significant economic losses in beef and dairy herds. This syndrome is usually difficult to diagnose. The aim of this study was to characterize bovine abortion causes in Argentina by standard diagnosis procedures (histology, bacterial and viral isolation) and other diagnostic tests like direct fluorescent antibody test (DFAT), fetal serology, immunohistochemistry (IHC), and PCR, showing their specific advantages and limitations. Necropsies were performed in 150 aborted bovine fetuses submitted to the diagnostic laboratories of Instituto Nacional de Tecnología Agropecuaria (INTA) Balcarce, Argentina. Etiological diagnosis was confirmed in 78 fetuses (52% of the cases). Most causes of abortion were of infectious origin, being Neospora caninum (14.67%), Campylobacter fetus sp. (9.33%), Leptospira spp. (7.33%) and Brucella abortus (6.65%) the main microorganisms identified. Bovine viral diarrhea virus (BVDV) and bovine herpes virus (BHV) were diagnosed in 2 (1.33%) and 3 (2%) cases, respectively. This study showed a better characterization of bovine abortion compared with previous researches done on this topic. [Tendências atuais do aborto bovino na Argentina.] O aborto bovino é uma causa importante de perdas econômicas significativas em rebanhos bovinos e leiteiros. Esta síndrome é geralmente difícil de diagnosticar. O objetivo deste estudo foi caracterizar o aborto bovino na Argentina por procedimentos diagnósticos de rotina (histologia, isolamento viral e bacteriana) e outros testes diagnósticos como ensaio directo de anticorpos fluorescentes (DFAT), sorologia fetal, imuno-histoquica (IHC), e PCR; mostrando suas vantagens e limitações específicas. As necropsias foram realizadas em 150 fetos bovinos abortados submetidos aos laboratórios de diagnóstico do Instituto Nacional de Tecnologia Agropecuária (INTA) de Balcarce, na Argentina. O diagnóstico etiológico foi confirmado em 78 fetos (52% dos casos). A maioria das causas de aborto foram de origem infecciosa, sendo Neospora caninum (14,67%), Campylobacter fetus sp. (9,33%), Leptospira spp. (7,33%) e Brucella abortus (6,65%) os principais microrganismos identificados. O vírus da diarréia viral bovina (BVDV) e o herpesvírus bovino (BHV) foram diagnosticados em 2 (1,33%) e 3 (2%) casos, respectivamente. Este estudo mostrou uma melhor caracterização do aborto bovino em comparação com pesquisas anteriores feita sobre este tema. O aborto bovino é uma causa importante de perdas econômicas significativas em rebanhos bovinos e leiteiros. Esta síndrome é geralmente difícil de diagnosticar. O objetivo deste estudo foi caracterizar o aborto bovino na Argentina por procedimentos diagnósticos de rotina (histologia, isolamento viral e bacteriana) e outros testes diagnósticos como ensaio directo de anticorpos fluorescentes (DFAT), sorologia fetal, imuno-histoquica (IHC), e PCR; mostrando suas vantagens e limitações específicas. As necropsias foram realizadas em 150 fetos bovinos abortados submetidos aos laboratórios de diagnóstico do Instituto Nacional de Tecnologia Agropecuária (INTA) de Balcarce, na Argentina. O diagnóstico etiológico foi confirmado em 78 fetos (52% dos casos). A maioria das causas de aborto foram de origem infecciosa, sendo Neospora caninum (14,67%), Campylobacter fetus sp. (9,33%), Leptospira spp. (7,33%) e Brucella abortus (6,65%) os principais microrganismos identificados. O vírus da diarréia viral bovina (BVDV) e o herpesvírus bovino (BHV) foram diagnosticados em 2 (1,33%) e 3 (2%) casos, respectivamente. Este estudo mostrou uma melhor caracterização do aborto bovino em comparação com pesquisas anteriores feita sobre este tema. EEA Balcarce Fil: Morrell, Eleonora Lidia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina. Fil: Campero, Carlos Manuel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina. Fil: Cantón, Germán.José. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina. Fil: Odeón, Anselmo Carlos. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina. Fil: Moore, Dadín Prando. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fil: Odriozola, Ernesto Raúl. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina. Fil: Paolicchi, Fernando. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina. Fil: Fiorentino, María Andrea. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.

The aim of this study was to evaluate delayed type hypersensitivity (DTH) induced by the intradermal inoculationof a Neospora caninum tachyzoite soluble lysate in cattle previously exposed with the protozoa. Fourexperimental groups were selected according to the prior exposure to N. caninum antigen. All cows were intradermallyinjected with a N. caninum tachyzoite soluble lysate and skinfold thickness growth at the inoculationsites was measured at 0, 24, 48, 72 and 96 h post inoculation (hpi). Additionally, specific antibodies and IFN-γproduction were assessed. Cows experimentally infected with live N. caninum tachyzoites and cows naturallyexposed to N. caninum developed skin reactions compatible with DTH between 24 and 96 hpi (p < 0.05).Moreover, cows inoculated with an experimental N. caninum vaccine and cows without evidence of exposure toN. caninum did not show a significant increase in skin thickness (p > 0.05). Furthermore, serological status ofthe animals was not modified due to the intradermal inoculation. The highest IFN-γ production was observed at15 days after intradermal inoculation (p < 0.05). Therefore, these results suggest that cattle previously exposedto N. caninum develop a reaction compatible with DTH which could be useful as in vivo cell mediated immunityparameter for assessed bovine neosporosis. Fil: Fiorani, Franco. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina Fil: Armendano, Joaquín Ignacio. Instituto Nacional de Tecnología Agropecuaria; Argentina Fil: Hecker, Yanina Paola. Instituto Nacional de Tecnología Agropecuaria; Argentina Fil: Araoz, Virginia. Instituto Nacional de Tecnología Agropecuaria; Argentina Fil: Cantón, Germán J.. Instituto Nacional de Tecnología Agropecuaria; Argentina Fil: Leunda, María R.. Instituto Nacional de Tecnología Agropecuaria; Argentina Fil: Pereyra, Susana B.. Instituto Nacional de Tecnología Agropecuaria; Argentina Fil: Corva, Pablo M.. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina Fil: Odeón, Anselmo C.. Instituto Nacional de Tecnología Agropecuaria; Argentina Fil: Moore, Dadín P.. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Se describe un presunto caso de intoxicación con ionóforos en búfalas de un tambo de la Provincia de Buenos Aires, Argentina, las cuales habían consumido pasturas y ración comercial formulada para bovinos en ordeñe, conteniendo monensina. Murieron 5 de las 50 búfalas en ordeñe, manifestando taquipnea, disnea, sialorrea, decúbito y muerte. Durante la necropsia se observó hidrotórax, ascitis, hígado con puntillado hemorrágico, edema en vesícula biliar, duodeno y diafragma, así como coloración blanquecina en miocardio. Microscópicamente se evidenciaron miocarditis y miositis necrotizante no supurativa, hepatitis centrolobulillar necrotizante y edema pulmonar severo. La actividad de las enzimas creatinfosfoquinasa y aspartato amino transferasa estaba elevada en animales muestreados al azar. Los datos anamnésicos y clínico-patológicos fueron suficientes para determinar a la intoxicación por ionóforos como el diagnóstico presuntivo de esta mortandad, siendo éste el primer reporte en búfalos de Argentina. A presumptive ionophore intoxication in a water buffalo dairy herd from Buenos Aires Province, Argentina, is presented. Buffaloes were grazing pastures and were supplemented with a pelleted ration formulated for dairy cattle, that included monensin in its composition. Five out of 50 lactating buffaloes showed tachypnea, dyspnea, sialorrhea, sternal decubitus and death. During post mortem examination hydrothorax, ascites, hemorrhagic centrilobular hepatitis, edematous thickening of the gallbladder, duodenum and diaphragm muscle and light-colored areas in the myocardium, were observed. Microscopically, moderate multifocal non-suppurative necrotizing myocarditis and myositis, severe centrilobular necrohemorrhagic hepatitis and severe pulmonary edema, were found. CPK and AST enzyme activities were significantly elevated in randomly samples buffaloes. Information from anamnesis together with clinicopathological findings are in concordance with natural and experimental ionophore poisoning. This is the first report of toxicity in water buffaloes in Argentina, a highly susceptible animal species to ionophores poisoning. EEA Balcarce Fil: Bence, A.R. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias; Argentina. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina. Fil: García, J. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina. Actividad Privada; Argentina. Fil: Fernández, Eduardo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina. Fil: Morrell, Eleonora. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina. Fil: Cantón, Germán José. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.

En el sudeste de Córdoba y el sudoeste de Santa Fe, han proliferado sistemas de engorde a corral (EC) de bovinos, con creciente inclusión de burlanda de maíz húmeda (BMH) en sus dietas. Según antecedentes de altas concentraciones de azufre (S) en dicho alimento, y de sulfatos (SO4 ) en el agua de bebida de la región, podría existir un excesivo aporte dietético de S total. En ECs de la región se han comunicado problemáticas productivo-sanitarias compatibles con las causadas por exceso de S dietético, asociadas al consumo de BMH y/o agua de bebida con altas concentraciones de SO4 . El objetivo del presente trabajo fue estimar y evaluar la concentración de S total en las dietas de bovinos de EC en la mencionada región del país. En verano e invierno del año 2017 se recolectaron muestras de agua de bebida de 46 establecimientos para cuantificar la concentración de SO4 , y se recolectaron muestras de 26 lotes de BMH provenientes de la planta industrial abastecedora de la región en estudio para la determinación de S total. La estimación de la concentración de S dietético total se realizó para cada perforación de agua, considerando el aporte del alimento sólido como el del agua de bebida. La estimación del S aportado por el alimento sólido se realizó considerando el aporte de dietas estándar de EC con 0 (B0), 15 (B15), 30 (B30) y 45% (B45) de BMH. Las concentraciones medias de SO4 en el agua fueron de 196 y 90 mg/l, en los muestreos estival e invernal respectivamente. La concentración media de S en BMH fue de 0,68%. Las concentraciones medias estimadas de S total en verano fueron de 0,23, 0,29, 0,34 y 0,43% para las dietas B0, B15, B30 y B45 respectivamente, mientras que en el invierno fueron de 0,22, 0,28, 0,33 y 0,42% para las dietas B0, B15, B30 y B45 respectivamente. En la región estudiada, es poco probable que los niveles de S dietético sean perjudiciales para la salud y desempeño de bovinos de EC. In the southeast of Córdoba and southwest of Santa Fe provinces, feedlot cattle (FC) systems have proliferated, with the inclusion of wet corn destillers grains (WCDG) in their diets. According to the background of high concentrations of sulfur(S) in WCDG, and sulfates (SO4) excess in drinking water of the region, an excessive dietary S is possible. Productive-health problems have been reported in FC from this region, compatible with those caused by excessive dietary S, associated with WCDG and / or high SO4 drinking water consumption. The objective of the present work was to estimate and evaluate the concentration of total S in the FC diets in this region of Argentina. During the summer and winter of 2017, drinking water samples were collected from 46 farms in order to quantify SO4 concentration and twenty-six WCDG batches from the regional supply plant were sampled for total S determination. The estimation of dietary S concentration was performed for each water well, considering solid food and drinking water contribution. The estimation of S solid food contribution was performed considering the contribution of standard FC diets with 0 (B0), 15 (B15), 30 (B30) and 45% (B45) WCDG inclusion. The average water SO4 concentrations were 196 and 90 mg/l, in the summer and winter samples, respectively. The average WCDG S content was 0.68%. Estimated total dietary S averages in summer were 0,23, 0,29, 0,34 and 0,43% for B0, B15, B30 and B45 diets respectively, while in winter they were 0,22, 0,28, 0,33 and 0,42% for B0, B15, B30 and B45 diets, respectively. In most FC farms from the studied region, it is unlikely that dietary S levels are detrimental to health and productive performance of FC. EEA Balcarce Fil: Castro, Damián Jesús. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Marcos Juárez. Producción Porcina Sanidad Animal; Argentina. Fil: Poo, Juan Ignacio. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina. Fil: Brambilla, Emilio Cesar. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina. Fil: Fernández, Eduardo Luján. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina. Fil: Cantón, Germán José. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.

The aim of this study is to provide preliminary data about the occurrence of N. caninum- and T. gondii-related abortions and perinatal deaths in sheep from Argentina. Thirty ovine aborted foetuses and 33 perinatal deaths were submitted to the Veterinary Diagnostic Service at INTA EEA Balcarce (Argentina) during 2017–2019. A complete necropsy was performed on all specimens submitted, and foetal and placental tissues were examined. Foetal cavity fluids were collected for assessment of antibodies to N. caninum and T. gondii by indirect fluorescent antibody technique (IFAT). Placental and foetal tissue samples were collected for DNA extraction and histopathological analysis. The differential diagnosis with other causes of abortion was carried out. Of the sampled specimens, 20.63% (13/63) displayed evidence for N. caninum infection by IFAT and PCR, and in 61.5% (8/13) of the positive specimens the parasite was confirmed as the cause of abortion/perinatal death based on the presence of compatible histological lesions and/or positive immunohistochemistry test, positive PCR and/or positive IFAT, and no other infectious agents diagnosed. In contrast, T. gondii infection was confirmed in 9.52% (6/63) of the analysed specimens, but only in 2 lambs T. gondii was determined as the death cause. Neospora caninum and T. gondii co-infections were confirmed in 4 analysed specimens (2 aborted foetuses and 2 perinatal deaths). These results demonstrated that N. caninum is efficiently transmitted and a frequent cause of ovine reproductive failure in the commercial analysed flocks compared with T. gondii. Despite T. gondii congenital infection was detected in some specimens (6/63), it was confirmed as the cause of death in only two of them. Thus, and considering the limited availability of confirmed samples, we could not determine whether toxoplasmosis is a major problem in Argentinian sheep flocks or not. More studies on a greater number of specimens from different ovine production systems under different management conditions are necessary to assess the real impact of neosporosis and toxoplasmosis in Argentina. EEA Mercedes Fil: Della Rosa, Paola. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mercedes; Argentina Fil: Fiorentino, María Andrea. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce. Laboratorio de Bacteriología; Argentina Fil: Morell, Eleonora Lidia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce. Laboratorio de Patología; Argentina. Fil: Scioli, María Valeria. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina. Fil: Paoliochi, Fernando. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce. Laboratorio de Bacteriología; Argentina Fil: Moore, Dadín. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina. IPADS Balcarce. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fil: Cantón, Germán Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina. Fil: Hercker, Yanina. IPADS Balcarce. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.

Delayed-type hypersensitivity (DTH) has been used in human and veterinary medicine as a skin testing for evaluating in vivo cell-mediated immune responses (CMIR). Whereas CMIR is a key process to control intracellular pathogens, its value at identifying cattle exposed to the abortigenic intracellular coccidian parasite Neospora caninum is unknown. In this work, we have evaluated a DTH skin testing in cattle exposed to N. caninum and still seronegative. Female calves were experimentally sensitized by subcutaneous (SC) inoculation with live tachyzoites of N. caninum (NC-Argentina LP1) in sterile phosphate-buffered saline (PBS) (group A; n: 8) whereas other calveswere mock-sensitized with PBS (group B; n: 6). Two DTH skin tests were performed by intradermal inoculation with a soluble lysate of N. caninum tachyzoites (NC-Argentina LP1) in the neck region at 60d and 960 d after sensitization. Skinfold thickness at the intradermal inoculation site was measured at 0, 24, 48 h post each DTH skin test and skin biopsies taken for microscopic evaluation. Specific N. caninum antibodies kinetics was evaluated all throughthe experiment. We found that whereas N. caninum specific antibodies remained below the ELISA cut-off, a distinctive skinfold thickness increase was detected in sensitized animals (group A) at the DTH skin test site, showing induration, swelling and inflammatory infiltration. Mock sensitized animals (group B) showed no skinfold thickness growth and lacked specific antibody response. Thus, N. caninum DTH skin testing could be a useful diagnostic tool for the detection of CMIR during N. caninum infection in non-humoral responders.

The aim of this study was to describe the frequency of ovine specific antibodies to Toxoplasma gondii, Neospora caninum and Sarcocystis spp. and to estimate different transmission routes of these infections. One hundred and thirty Texel sheep and their 117 Texel lambs were included in the study. Serum samples were tested for antibodies to T. gondii, N. caninum and Sarcocystis spp. using IFAT. Toxoplasma gondii seroprevalence was 10.00% in sheep (IC95%: 4.80-15.20%), being higher in adult sheep (≥12 year) than in younger sheep (OR 1.30; 95% CI, 1.10-1.50). N. caninum and Sarcocystis spp. seroprevalences were 1.54% (IC95%: 0.00-5.70) and 72.09% (IC95%: 67.70-82.70), respectively, with no association between age and seropositivity in sheep (P>0.05). T. gondii seroprevalence in lambs was 4.27% (IC95%: 0.61-7.94). No association between T. gondii serological status in sheep and their lambs was detected (P = 0.07). Two T. gondii and Sarcocystis spp. seropositive lambs were euthanized and T. gondii and Sarcocystis spp. DNA was detected by PCR in their tissues. In conclusion, the increase of T. gondii seropositivity in relationship with sheep age and the lack of association between sheep-lamb serological status, suggest that horizontal infection is the main transmission route in this flock as reported before. Due to the low number of N. caninum-seropositive ewes no assumptions can be done about the impact of this parasite in this flock. According with previous reports, the main transmission route for Sarcocystis spp. in this species in the present study was horizontal., Facultad de Ciencias Veterinarias

White muscle disease (WMD), nutritional myodegeneration or enzootic muscular dystrophy, is a nutritional condition associated with selenium and/or vitamin E deficiency in ruminants. These elements are constituents of the major body antioxidant systems. Depletion of selenium results in oxidative damage to cardiac and skeletal muscle cells, resulting in myodegeneration and myonecrosis, typical lesions of WMD. Selenium deficiency is common in South America, but WMD is underreported. This research describes clinical, biochemical and pathological findings in two episodes of WMD associated with selenium deficiency in beef and dairy calves in Argentina and Uruguay with concurrent copper deficiency in one of them, which resulted in spontaneous calf mortality. Further studies are necessary to estimate the true incidence and economic impact of clinical and subclinical mineral deficiencies in livestock production systems in the southern cone of South America. Doença do músculo branco (DMB), miodegeneração nutricional ou distrofia muscular enzoótica é uma condição nutricional associada à deficiência de selênio e/ou vitamina E em ruminantes. Esses elementos são constituintes dos principais sistemas antioxidantes do corpo. O esgotamento de selênio resulta em dano oxidativo às células musculares cardíacas e esqueléticas, resultando em miodegeneração e mionecrose, lesões típicas da DMB. A deficiência de selênio é comum na América do Sul, mas a DMB está subnotificada. Este trabalho descreve os achados clínicos, bioquímicos e patológicos em dois surtos de DMB associados à deficiência de selênio em bezerros para carne e leite na Argentina e Uruguai com concomitante deficiência de cobre em um surto, que resultaram em mortalidade espontânea de bezerros. São necessários mais estudos para estimar a verdadeira incidência e impacto econômico das deficiências minerais clínicas e subclínicas nos sistemas de produção pecuária no sul da América do Sul. EEA Cuenca del Salado Fil: Rodriguez, Alejandro Martin. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Cuenca del Salado; Argentina Fil: Schild, Carlos Omar. Instituto Nacional de Investigación Agropecuaria (INIA), La Estanzuela; Uruguay Fil: Canton, German Jose. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina Fil: Riet‐Correa, Franklin. Instituto Nacional de Investigación Agropecuaria (INIA), La Estanzuela; Uruguay Fil: Armendano, Joaquín Ignacio. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina Fil: Caffarena, Rubén Dario. Instituto Nacional de Investigación Agropecuaria (INIA), La Estanzuela; Uruguay Fil: Brambilla, Emilio Cesar. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina Fil: García, Juan Agustín. Universidad de la República. Centro Universitario Regional Este; Uruguay Fil: Morrell, Eleonora Lidia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina Fil: Poppenga, Robert. University of California at Davis. School of Veterinary Medicine. California Animal Health and Food Safety (CAHFS). Laboratory; Estados Unidos Fil: Giannitti, Federico. Instituto Nacional de Investigación Agropecuaria (INIA), La Estanzuela; Uruguay. University of Minnesota. College of Veterinary Medicine. Veterinary Population Medicine Department; Estados Unidos

The work describes a case of Sarcocystis gigantea infection in a 3-years-old Corriedale ewe from Buenos Aires Province, Argentina. The ewe was found dead with a poor body condition. Pathological and molecular studies were carried out in order to try and confirm the causative agent of the infection. At necropsy, approx. 100 whitish elliptic (3–5 mm to 5–8 mm) macrocysts with a hard consistency were observed along the esophageal and pharyngeal muscular layers. Microscopically, the macrocysts consisted of an eosinophilic wall, internal septa originated from the eosinophilic wall and basophilic parasitic cells were located among the septa. The sarcocysts were identified molecularly through PCR amplification and sequencing of a short segment of the 18S rRNA gene. Sequence analysis of the amplified DNA demonstrated 100% identity to S. gigantea sequences previously published. To our knowledge this is the first molecular confirmation of S. gigantea infection in sheep in the Americas. Fil: Gual, Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina Fil: Bartley, Paul M.. Pentlands Science Park. Moredun Research Institute; Reino Unido Fil: Katzer, Frank. Pentlands Science Park. Moredun Research Institute; Reino Unido Fil: Innes, Elisabeth A.. Pentlands Science Park. Moredun Research Institute; Reino Unido Fil: Canton, German. Instituto Nacional de Tecnología Agropecuaria; Argentina Fil: Moore, Dadin Prando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina

Neospora caninum is an obligate parasite and a major cause of abortion in cattle. Pregnancy failures appear to be associated with weak innate defences on the maternal-fetal interface during infection with N. caninum. Herein, we studied the gene expression of Toll-like receptors (TLRs) in pregnant heifers immunized with different vaccine formulations against N. caninum before mating and then challenged the heifers with live N. caninum on day 70 of gestation. TLR7 and TLR8 expression was upregulated in the placental caruncle of infected-pregnant heifers previously exposed to live N. caninum as immunogen. However, TLR7 and 8 expression in both placenta and caruncle as well as, TLR3 and 9 expression in caruncle were upregulated when heifers were previously immunized with inactivated soluble whole antigens and recombinant NcSAG1, NcHSP20 and NcGRA7 proteins. All dams were carrying viable fetuses when they were culled at day 104 of gestation. Upregulation of TLR7 and IFNγ expression was detected in fetal spleen when their mothers where previously vaccinated with soluble antigens and recombinant NcSAG1, NcHSP20 and NcGRA7 proteins. These studies demonstrate that soluble or recombinant NcSAG1, NcHSP20 and NcGRA7 antigens induce key TLRs expression at the maternal-fetal interface, probably triggering damaging inflammatory cellular immune responses associated with abortion. Previous infection with N. caninum seems to attenuate the innate immune response at the maternal-fetal interface, which could favour pregnancy maintenance and perpetuation of the disease. This finding represents novel information on how N. caninum vaccination and infection modulate TLRs expression at the placenta and fetal spleen, the possible role in the pregnancy outcomes and transplacental transmission of the protozoa. Fil: Marin, Maia Solange. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Hecker, Yanina Paola. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Quintana, S.. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología; Argentina Fil: Perez Luna, Sandra Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; Argentina Fil: Leunda, Maria Rosa. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; Argentina Fil: Canton, German. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; Argentina Fil: Cobo, Eduardo Ruben. University of Calgary; Canadá. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Moore, Dadin Prando. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Odeón, Anselmo Carlos. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; Argentina

A retrospective analysis (2000 to 2013) of cattle poisoning caused by toxic plants and other compounds was carried out in the Pampas region of Argentina by the Animal Health Group of INTA-EEA, Balcarce. During this period, 1263 reports of diseases of different etiologies (infectious, parasitic, toxic, metabolic and miscellaneous) were recorded in cattle, by collecting anamnestic, clinical and pathological information. A toxic etiology was diagnosed in 21.1% of these reports. Iatrogenic poisoning caused by ionophores was the most frequently recorded etiology. Consumption of toxic plants (Wedelia glauca, Solanum glaucophyllum, among others), mycotoxins (Claviceps purpurea, Claviceps paspali, Epichloë coenophiala, among others), and plants producing cyanide and nitrates/nitrites were also commonly diagnosed. The high frequency of toxic episodes and the difficulties in their diagnosis by practitioners in our livestock production systems emphasizes the importance of this report. EEA Balcarce Fil: García, Juan Agustín. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina Fil: Canton, German Jose. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina Fil: Spath, Ernesto Juan. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina Fil: Odriozola, Ernesto Raul. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina Fil: Garcia, Bernardo L. Actividad Privada; Argentina Fil: Micheloud, Juan Francisco. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Salta; Argentina Fil: Campero, Carlos Manuel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina

Innate immune responses at the maternal-fetal interface are key in the pathogenesis of Neospora caninum, an obligate parasite that causes abortion in cattle. Herein, we determined the gene expression of endosomal Toll-like receptors (TLRs) in the placenta and fetuses from both non-infected pregnant heifers and pregnant heifers intravenously challenged with live tachyzoites of N. caninum on day 70 of gestation. On day 104 of pregnancy, mRNA expression of TLRs 3 and 8, as well as that of TLRs 7 and 9, was high in the spleen of fetuses from N. caninum-infected heifers. Gene expression levels of endosomal TLRs were also detectable in the placenta and the maternal caruncle from infected heifers, being TLRs 3, 7 and 8 particularly upregulated, mostly in the caruncle. Basal TLR levels were higher in fetal spleen than in placental tissues. This study provides novel information on how innate TLR responses are induced at the maternal-fetal interface of cattle in response to intracellular N. caninum. Fil: Marin, Maia Solange. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; Argentina Fil: Hecker, Yanina Paola. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; Argentina Fil: Quintana, Silvina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología; Argentina Fil: Perez, Sandra. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; Argentina Fil: Leunda, Maria Rosa. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; Argentina Fil: Canton, German. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; Argentina Fil: Cobo, Eduardo Ruben. University of Calgary; Canadá Fil: Moore, Dadin Prando. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; Argentina Fil: Odeón, Anselmo Carlos. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; Argentina

13 páginas, 4 tablas, 2 figuras., Neospora caninum is recognized as a major cause of reproductive losses worldwide but its pathogenesis is not completely understood. Immune mediated placental pathology has been reported as being responsible for compromising pregnancy probably due to the adverse effects of exacerbated Th1 type response at the maternal-foetal interface. Different clinical outcomes are known to occur following experimental infections of cattle at different stages of gestation, with foetal death being the most common finding during early gestation, and the birth of live congenitally infected calves following infection later in gestation. The aim of the current study was to characterize the cytokine expression in the placenta of cattle experimentally challenged with tachyzoites of the Nc-1 strain during early, mid and late gestation. Moderate to severe infiltration of IL-12, IFN-γ and TNF-α expressing cells was observed in the placentas collected at early gestation and this infiltration was more pronounced in the samples collected from challenged dams carrying non-viable foetuses, compared with the mothers carrying viable foetuses. In contrast, the infiltration of Th1 cytokine expressing-cells was mild following N. caninum infection in mid gestation and scarce during infection in late gestation. Scarce expression of IL-4 was observed in the placentas from N. caninum-challenged and negative control animals throughout gestation. The milder Th1 immune response observed during later stages of gestation following Nc-1 infection could partially explain the less severe clinical outcome when compared to early pregnancy. © 2014 Elsevier B.V., The authors acknowledge the Scottish Government's Rural and Environment Science and Analytical Services Division (RESAS), UK, and Instituto Nacional de Tecnología Agropecuaria (INTA), Argentina.

Neospora caninum infection in cattle stimulates host immune responses, which may be responsible for placental damage leading to abortion. Susceptibility of water buffaloes (Bubalus bubalis) to neosporosis is not well understood, although vertical transmission and fetal death have been documented. The aim of this study was to characterize the immune response in the placentome of water buffalo following experimental infection in early gestation with the Nc-1 strain of N. caninum. Placentomes were examined by immunohistochemistry using antibodies specific for T-cell subsets, natural killer cells and CD79αcy cells. Placental inflammation was characterized by the infiltration of CD3+ and CD4+ T cells and T cells expressing the γδ T-cell receptor. The distribution of these cellular subsets in buffalo placentomes was similar to that previously described in cattle infected with N. caninum in early gestation, but the lesions were milder, which may explain the lower number of abortions observed in this species after infection. EEA Balcarce Fil: Canton, German Jose. Moredun Research Institute; Reino Unido. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina Fil: Konrad, Jose Luis. Universidad Nacional del Nordeste. Facultad de Veterinaria; Argentina Fil: Moore, Prando Dadin. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Caspe, Sergio Gaston. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mercedes; Argentina Fil: Palarea-Albaladejo, Javier. Biomathematics & Statistics Scotland; Reino Unido Fil: Campero, Carlos Manuel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina Fil: Chianini, Francesca. Moredun Research Institute; Reino Unido

Neospora caninum is a protozoan parasite known as an important cause of bovine abortion worldwide. Little is currently known about how different strains of N. caninum vary in their pathogenicity. In this study, we compared a Brazilian strain, Nc-Bahia, with the first isolate of this coccidian, Nc-1. Eight cows and seven buffaloes were submitted to fixed-time artificial insemination protocols for a better control of pregnancy. Group 1 was inoculated with Nc-Bahia (n = 8; five cows and three buffaloes), and Group 2 was inoculated with Nc-1 (n = 5; two cows and three buffaloes). One nonpregnant female of each species was left uninfected as sentinel controls for potential environmental infection. All inoculated animals received 5 × 10(8) tachyzoites of N. caninum, by intravenous route, on the 70th day of gestation. Uninfected animals remained seronegative throughout the experiment, indicating no exogenous infection, whereas all inoculated animals became seropositive to N. caninum. In Group 1, abortion was found in only one cow on 42 days postinfection (dpi; frequency of abortion = 12.5%), whilst all animals from Group 2 aborted on 35 dpi (frequency of abortion = 100%). Parasite DNA was detected by seminested PCR in maternal, foetal and placental tissues, confirming vertical transmission in Groups 1 and 2, although histological lesions had different frequencies and degrees of severity between the groups. There was evidence of lower pathogenicity of Nc-Bahia compared to Nc-1 when used in experimental infection, as it caused fewer abortions, as well as less frequent and milder histological lesions. This was the first time Nc-Bahia has been used for experimental infection.

The purpose of this work was to characterize the cellular phenotype in inflammatory infiltrates of fetal tissues from pregnant heifers immunized and experimentally challenged with Neospora caninum. Fetuses from 20 heifers separated into 5 groups were obtained. The experiment was designed as follow: Group A, heifers inoculated intravenously with live tachyzoites of Argentine strain NC-6 (n = 4); Group B heifers inoculated subcutaneously with soluble native antigen from the same strain formulated with immune stimulant complexes (ISCOMs) (n = 4); Group C heifers inoculated with recombinant proteins, rNcSAG1, rNcHSP20, rNcGRA7 formulated with ISCOMs (n = 4), Group D heifers inoculated subcutaneously with sterile phosphate buffered solution (n = 4) and Group E heifers inoculated subcutaneously with antigen-free ISCOMs (n = 4). Experimental challenge was performed at 70 days of gestation and all heifers were euthanized 34 days later. Fetal tissues were taken for histological studies. Inflammatory lesions were observed in brain and lung, and immunhistochemistry was used to identify CD3+, CD20+ and MHC II+ cells. The majority of the cells that infiltrate and circumscribe the lesions in the brain and lung tissue expressed MHC II antigen; varying between 70–90% of the total cellular infiltrate. CD3+ cells were also present within the lesions, contributing to up to 30% of the inflammatory cells. CD20+ cells appeared as a marginal group, in some cases, with a range between 10 and 25%. As expected, the immunolabeling of MHC II + and CD3 + cells in fetal tissues was associated with fetal infection with N. caninum. There were statistically significant differences in the distribution and population of the inflammatory infiltrate in relation to the immunogenic treatment and the type of tissue, with inflammatory cells being markedly less extensive fetuses from group A (dams previously exposed to N. caninum) and in brain tissue. This work showed that Neospora-infection induced MHC II+ and CD3+ cells in bovine fetuses from dams receiving experimental vaccines.

Previous work carried out to characterise different immune cells in ruminant placentas found strong CD79αcy nuclear labelling in cells histologically resembling trophoblast cells. In the attempt to characterize this cell population, placentomes collected from cattle, sheep and water buffaloes were examined by immunohistochemistry with single and double labelling using monoclonal antibodies (mAb) against B lymphocytes and trophoblast cells. Most CD79αcy + cells co-expressed placental lactogen or cytokeratin and were CD21 and MHC class II negative strongly suggesting they do not have a B cell origin. However, a potential immunological role of these cells cannot be ruled out and it is currently unknown if the findings described may have an impact on physiological knowledge, health, and or diseases pathogenesis in ruminants.