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Bovine viral diarrhoea (BVD) is one of the most economically damaging livestock enzootic diseases in the world. BVD aetiological agents are three pestiviruses (BVDV-1, -2 and HoBi-like pestivirus), which exhibit high genetic diversity and complex transmission cycles. This considerably hampers the management of the disease, which is why eradication plans have been implemented in several countries. In France, a national plan has been in place since 2019. Our understanding of its impact on the distribution of BVDV genotypes is limited by the availability of French genetic data. Here, we conducted a molecular epidemiology study to refine our knowledge of BVDV genetic diversity in France, characterise its international relationships, and analyse national spatio-temporal genotypic distribution. We collated 1037 BVDV-positive samples throughout France between 2011 and 2023, with a greater sampling effort in two major cattle production areas. We developed a high-throughput sequencing protocol which we used to complete the 5'UTR genotyping of this collection. We show that two main BVDV-1 genotypes, 1e and 1b, account for 88% of genotyped sequences. We also identified seven other BVDV-1 genotypes occurring at low frequencies and three BVDV-2 samples (genotype 2c). Phylogenetic analyses indicate different worldwide distribution patterns between the two main BVDV-1 genotypes. Their relative frequencies present no major changes in France since the 1990s and few variations at the national scale. We also found some degree of local spatial structuring in western France. Overall, our results demonstrate the potential of large-scale sequence-based surveillance to monitor changes in the epidemiological situation of enzootic diseases., (© 2024. The Author(s).)

A total of 752 horses were involved in the CES Valencia Spring Tour 2021. Due to an equine herpesvirus-1 (EHV-1) outbreak, the competition was cancelled and the site was locked down. The objective of this study was to describe epidemiological, clinical, diagnostic, and outcome data of the 160 horses remaining in Valencia. Clinical and quantitative polymerase chain reaction (qPCR) data were analysed for 60 horses in a retrospective case-control observational study. The risk of developing clinical manifestations was explored using a logistic regression approach. EHV-1 was detected by qPCR, genotyped as A2254 (ORF30) and isolated on cell culture. From the 60 horses, 50 (83.3%) showed fever, 30 horses (50%) showed no further signs and 20 (40%) showed neurological signs, with eight horses (16%) hospitalised, of which two died (3%). Stallions and geldings were six times more likely to develop EHV-1 infection compared to mares. Horses older than 9 years, or housed in the middle of the tent were more likely to develop EHV-1 myeloencephalopathy (EHM). These data show that for EHV-1 infection, the risk factor was male sex. For EHM the risk factors were age > 9-year old and location in the middle of the tent. These data highlight the crucial role of stable design, position, and ventilation in EHV-outbreaks. It also showed that PCR testing of the horses was important to manage the quarantine., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

Equine herpesvirus 1 isolates from a 2021 outbreak of neurologic disease in Europe have a mutation, A713G, in open reading frame 11 not detected in 249 other sequences from equine herpesvirus 1 isolates. This single-nucleotide polymorphism could help identify horses infected with the virus strain linked to this outbreak.

Background: Serological screening tests for Lyme borreliosis have poor specificity, with potential for misdiagnosis and unnecessary antimicrobial treatment., Objectives: To evaluate the impact of Lyme borreliosis seroprevalence and serologic test characteristics on the probability of obtaining a false-positive result and impact on antimicrobial use., Study Design: Cross-sectional serological survey and modelling., Methods: Sera from 303 horses in southern Belgium were analysed by enzyme-linked immunosorbent assay (ELISA). Apparent seroprevalence was derived from serological data and a Bayesian estimate of true seroprevalence was computed. These were a starting point to model the impact of test and population characteristics on the probability of obtaining false-positive results and consequently unnecessary treatments and complications., Results: Apparent and true seroprevalence were 22% (95% CI 18%-27%) and 11% (credible interval with 95% probability 0.6%-21%) respectively. We estimate that two-thirds of positive samples are false positive in southern Belgium, with one in five of tested horses potentially misdiagnosed as infected. Around 5% of antimicrobial use in equine veterinary practice in Belgium may be attributable to treatment of a false-positive result., Main Limitations: There was uncertainty regarding the ELISA's sensitivity and specificity., Conclusions: This study highlights the importance of appreciating the poor diagnostic value of ELISA screening for Lyme borreliosis as demonstrated by this case study of seroprevalence in southern Belgium where we demonstrate that a nontrivial number of horses is estimated to receive unwarranted treatment due to poor appreciation of screening test characteristics by practitioners, contributing substantially to unnecessary use of antimicrobials., (© 2020 The Authors. Equine Veterinary Journal published by John Wiley & Sons Ltd on behalf of EVJ Ltd.)

(1) Background: Equine hepacivirus (EqHV), also referred to as non-primate hepacivirus (NPHV), infects horses-and dogs in some instances-and is closely related to hepatitis C virus (HCV) that has infected up to 3% of the world's human population, causing an epidemic of liver cirrhosis and cancer. EqHV also chronically infects the liver of horses, but does not appear to cause serious liver damages. Previous studies have been looking to identify route(s) of EqHV transmission to and between horses. (2) Methods: In this retrospective study, we sought to evaluate the prevalence of vertical transmission taking place in utero with measuring by quantitative RT-PCR the amounts of EqHV genome in samples from 394 dead foals or fetuses, paired with the allantochorion whenever available. (3) Results: Detection of EqHV in three foals most likely resulted from a vertical transmission from the mares to the fetuses, consistent with the in utero transmission hypothesis. In support of this observation, the presence of EqHV genome was found for the first time in two of the allantochorions. (4) Conclusions: As seemingly benign viruses could turn deadly (e.g., Zika flavivirus) and EqHV happens to have infected a significant proportion of the world's horse herds, EqHV infectious cycle should be further clarified.

Equid alpha-herpesviruses (EHV) are responsible for different diseases in equine population. EHV-1 causes respiratory diseases, abortions and nervous disorders, EHV-4 causes respiratory diseases and sporadic abortion, while EHV-3 is responsible of equine coital exanthema. In view of the lack of efficacy of vaccines against EHV-1 and EHV-4 and in the absence of vaccines against EHV-3, the use of antiviral treatment is of great interest. In this study, we documented the interest of the Real-Time Cell Analysis (RTCA) technology to monitor the cytopathic effects induced by these viruses on equine dermal cells, and established the efficacy of this method to evaluate the antiviral effect of aciclovir (ACV) and ganciclovir (GCV). In addition, the RTCA technology has also been found appropriate for the high-throughput screening of small molecules against EHV, allowing the identification of spironolactone as a novel antiviral against EHV., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Several Brucella isolates have been described in wild-caught and "exotic" amphibians from various continents and identified as B. inopinata -like strains. On the basis of epidemiological investigations conducted in June 2017 in France in a farm producing domestic frogs ( Pelophylax ridibundus ) for human consumption of frog's legs, potentially pathogenic bacteria were isolated from adults showing lesions (joint and subcutaneous abscesses). The bacteria were initially misidentified as Ochrobactrum anthropi using a commercial identification system, prior to being identified as Brucella spp. by MALDI-TOF assay. Classical phenotypic identification confirmed the Brucella genus, but did not make it possible to conclude unequivocally on species determination. Conventional and innovative bacteriological and molecular methods concluded that the investigated strain was very close to B. microti species, and not B. inopinata -like strains, as expected. The methods included growth kinetic, antimicrobial susceptibility testing, RT-PCR, Bruce-Ladder, Suis-Ladder, RFLP-PCR, AMOS-ERY, MLVA-16, the ectoine system, 16S rRNA and recA sequence analyses, the LPS pattern, in silico MLST-21, comparative whole-genome analyses (including average nucleotide identity ANI and whole-genome SNP analysis) and HRM-PCR assays. Minor polyphasic discrepancies, especially phage lysis and A-dominant agglutination patterns, as well as, small molecular divergences suggest the investigated strain should be considered a B. microti- like strain, raising concerns about its environmental persistence and unknown animal pathogenic and zoonotic potential as for other B. microti strains described to date.

Trypanosoma equiperdum, the causative agent of dourine, may affect the central nervous system, leading to neurological signs in infected horses. This location protects the parasite from most (if not all) existing chemotherapies. In this context, the OIE terrestrial code considers dourine as a non-treatable disease and imposes a stamping-out policy for affected animals before a country may achieve its dourine-free status. The use of practices as drastic as euthanasia remains controversial, but the lack of a suitable tool for studying a treatment's efficacy against dourine hampers the development of an alternative strategy for dourine infection management. The present study reports on the development of an experimental infection model for assessing drug efficacy against the nervous form of dourine. The model combines the infection of horses by Trypanosoma equiperdum and the search for trypanosomes in the cerebrospinal fluid (CSF) through an ultrasound-guided cervical sampling protocol. After a development phase involving four horses, we established an infection model that consists of inoculating 5 × 10 4 T. equiperdum OVI parasites intravenously into adult Welsh mares (Equus caballus). To evaluate its efficacy, eight horses were infected according to this model. In all these animals, parasites were observed in the blood at 2 days post-inoculation (p.i.) and in CSF (12.5 ± 1.6 days p.i.) and seroconversion was detected (8.25 ± 0.5 days p.i.). All eight animals also developed fever (rectal temperature > 39 °C), low hematocrit (< 27%), and ventral edema (7.9 ± 2.0 days p.i.), together with other inconstant clinical signs such as edema of the vulva (six out of eight horses) or cutaneous plaques (three out of eight horses). This model provides a robust infection protocol that induces an acute trypanosome infection and that allows parasites to be detected in the CSF of infected horses within a period of time compatible with animal experimentation constraints. We conclude that this model constitutes a suitable tool for analyzing the efficacy of anti-Trypanosoma drugs and vaccines., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Like hepatitis C virus (HCV) in humans, the newly identified equine hepacivirus (NPHV) displays a predominating liver tropism that may evolve into chronic infections. The genomes of the two viruses share several organizational and functional features and are phylogenetically closest amongst the Hepacivirus genus. A limited amount of data is available regarding the spread of hepacivirus infections in horses. In this study, we asked whether in a more representative sample the prevalence and distribution of NPHV infections in France would resemble that reported so far in other countries. A total of 1033 horses sera from stud farms throughout France were analysed by qRT-PCR to determine the prevalence of ongoing NPHV infections and viral loads; in positive samples, partial sequences of NPHV's genome (5'UTR, NS3 and NS5B genes) were determined. Serum concentrations of biliary acids, glutamate dehydrogenase (GLDH) and L-gamma-glutamyl transferase (γ-GT) were measured for most horses. We detected NPHV infections in 6.2% of the horses, a prevalence that reached 8.3% in thoroughbreds and was significantly higher than in other breeds. The presence of circulating virus was neither significantly associated with biological disturbances nor with clinical hepatic impairment. Our phylogenetic analysis was based on both neighbour-joining and maximum-likelihood approaches. Its result shows that, like almost everywhere else in the world so far, two major groups of NPHV strains infect French domestic horses. Based on genetic distances, we propose a classification into two separate NPHV subtypes. Viral loads in the serum of horses infected by the main subtype were, in average, four times higher than in those infected by the second subtype. We hypothesize that amino acid substitutions in the palm domain of NS5B between NPHV subtypes could underlie viral phenotypes that explain this result., (© 2016 Blackwell Verlag GmbH.)

Background: The potential involvement of viruses in inflammatory airway disease (IAD) was previously investigated through either serology or PCR from nasopharyngeal swabs (NS). The aims of this study were to determine the prevalence and incidence of viral genome detection by qPCR in the equine airways, and their association with respiratory clinical signs., Methods: Both NS and tracheal washes (TW) were collected monthly on 52 Standardbred racehorses at training, over 27 consecutive months (581 samples). Equid herpesviruses (EHV)-1, -4, -2 and -5, equine rhinitis virus-A and -B (ERBV), equine adenovirus-1 and -2, equine coronavirus and equine influenza virus were systematically investigated in both NS and TW. Nasal discharge, coughing, tracheal mucus score and TW neutrophil proportions were simultaneously recorded., Results: Genome for 7/10 viruses were detected at least once throughout the study; up to 4 different viruses being also concomitantly detected. Monthly incidence in TW was respectively 27.9% (EHV-5), 24.8% (EHV-2), 7.1% (ERBV), 3.8% (EHV-4), 1.9% (EAdV1) and 0.2% (EHV-1; ERAV). Neither agreement nor correlation between NS and TW was found for respectively genome detection and viral loads. Detection of viral genome in NS was not associated with any clinical sign. Coughing was significantly associated with TW detection of EHV-2 DNA (OR 3.1; P = 0.01) and ERBV RNA (OR 5.3; P < 0.001). Detection of EHV-2 DNA in TW was also significantly associated with excess tracheal mucus (OR 2.1; P = 0.02)., Conclusions: Detection and quantification of EHV-2 and ERBV by qPCR in TW, but not in NS, should be considered when investigating horses with IAD.

The aim of the study was to determine whether instillation of either 250 mL or 500 mL of saline for bronchoalveolar lavage (BAL) would influence cytological confirmation of inflammatory airway disease (IAD). Thirty client-owned Standardbred racehorses were sampled via endoscopy with 250 mL of saline in one lung and 500 mL in the contralateral lung. The procedure was repeated 72 h later, reversing the volume per lung. The proportions of BAL fluid (BALF) recovered were significantly higher and neutrophil percentages significantly lower with the larger volume. A poor agreement was found between methodologies in terms of final diagnosis, when based on proportions of neutrophils (>10% from at least one lung). Within the recommended range (250–500 mL), the instilled volume significantly influenced cytological profiles. Establishing specific BALF reference values is warranted.

Unlabelled: REASON FOR PERFORMING THIS STUDY: Equine influenza virus (EIV) is considered the most economically important equine respiratory pathogen worldwide. The H3N8 subtype, responsible for all outbreaks of equine influenza globally, evolves perpetually. Mutations in the genome of these viruses have the potential to modify their antigenic properties and recognition by pre-existing antibodies., Objectives: The aim of this study was to determine the genetic evolution of EIV strains in France and to compare it with the evolution of strains isolated globally. Analysis of the sequence data was performed to investigate any possible links between the outbreaks., Study Design: Retrospective genetic analysis study of archived material., Methods: Analyses were performed on the HA1 domain of haemagglutinin H3 of EIV isolated in a previous study carried out from November 2005 to October 2010. The nucleic acid sequence of 41 strains was analysed and translated. The French viruses were compared with 59 Clade 1 strains and 83 Clade 2 strains. Strains were aligned chronologically and on the basis of their geographical origin., Results: The 16 Clade 1 strains are all derived from the outbreak that started in the Grosbois training yard in 2009. The virus genome appears to have been stable during the outbreak. The 25 Clade 2 strains were isolated over the 5-year period during which several mutations had emerged. Some strains incorporate a sporadic mutation, and others a mutation that may occur several times but does not persist. However, all strains are gradually moving towards definitive mutations., Conclusion: This study demonstrated that EIVs have evolved in France during this period in a similar manner to EIVs globally. The data lend support to the current World Animal Health Organisation recommendation that the vaccines contain a representative of both Clade 1 and Clade 2 of the Florida sublineage.

Background: Multiple cytological patterns occur in bronchoalveolar lavage fluid (BALF) of horses with inflammatory airway disease (IAD). Only few data on BALF cytokine profiles are available for horses with IAD, and are limited to mRNA expression., Hypothesis/objective: Cytological profiles of IAD are associated with different BALF immunological pathways. To investigate BALF cytokine concentrations in a large number of horses with neutrophilic IAD., Animals: One hundred and thirty-eight client-owned Standardbred racehorses in active training., Methods: Prospective observational study. BALF samples were obtained from left and right lungs. Interleukin (IL)-4, interferon (IFN)-γ, and tumor necrosis factor (TNF)-α concentrations were determined by ELISA., Results: Fourteen horses had normal BALF cytological profiles and 56 exhibited evidence of bilateral neutrophilic IAD. Twenty-four horses showed BALF with, respectively, IAD- and CTL consistent cytology and were excluded; as were 44 horses because of evidence of pulmonary hemorrhage. TNF-α (56 ± 115 pg/mL; P = .034) and IFN-γ concentrations (104 ± 247 pg/mL; P = .044) were significantly higher for IAD horses, compared with controls (respectively 19 ± 41 and 80 ± 116 pg/mL). Horses with 'neutrophil' subtype had significantly higher IFN-γ concentrations (110 ± 154 pg/mL), than 'neutrophil/metachromatic' (56 ± 54 pg/mL; P = .028) and 'neutrophil/metachromatic/eosinophil' subtypes (44 ± 23 pg/mL; P = .012)., Conclusions and Clinical Importance: Cytokine concentrations in BALF suggested that neutrophilic IAD is associated with activation of the innate immune system and a possible T-helper (Th)-1 polarized response. This study also suggested that immunological pathways vary according to cytological IAD subtypes., (Copyright © 2014 by the American College of Veterinary Internal Medicine.)

The aim of this study was to investigate neutrophil stimulation following experimentally-induced airway inflammation in healthy horses. Six horses received dexamethasone and four were then inoculated with equid herpesvirus-2 (EHV-2). Significant neutrophilia was detected in tracheal wash and bronchoalveolar lavage fluid for up to 6 days. Concentrations of neutrophil elastase (NE) and myeloperoxidase (MPO) were significantly increased compared to baseline for up to 14 days in tracheal washes and both markers were significantly correlated with neutrophil counts. Serum levels of surfactant protein D were not significantly modified throughout the study. These results suggest that dexamethasone administration with or without EHV-2 inoculation is associated with a sustainable activation and degranulation of neutrophils in the trachea along with moderate modifications detectable in the lower airways., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

The aim of this study was to determine whether the lung side being sampled would significantly influence bronchoalveolar lavage (BAL) cytological profiles and subsequent diagnosis in Standardbred racehorses. One hundred and thirty-eight French Trotters in active training and racing were included in a prospective observational study. BAL was performed using videoendoscopy in both right and left lungs during summer meetings in 2011 (64 horses) and 2012 (74 horses). Cytological data performed 24h later from right and left lungs were compared and specifically used to classify horses as affected with exercise-induced pulmonary haemorrhage (EIPH), inflammatory airway disease (IAD), or were 'controls'. For IAD, cytological definition was based on two different cut off values. Neutrophil percentages, haemosiderophage percentages and the haemosiderophage/macrophage (H/M) ratios were significantly higher in the right compared to the left lung. Measures of intra-class correlation coefficients revealed a fair agreement between left and right lungs for percentages of mast cells, eosinophils, and for the H/M ratio, and a moderate agreement for neutrophil percentages. Fair to moderate agreements were observed between left and right lungs for the diagnosis of IAD and/or EIPH based on kappa coefficients. When sampling one lung only, the risk of incorrectly classifying a horse as a 'control' increased with the use of the restraint cut-off values for IAD. As BAL from one lung is not representative of the other lung in the same horse, both lungs should be sampled for a better assessment of lung cellularity and for a precise diagnosis of lower airway diseases., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Reasons for Performing the Study: The Réseau d'Epidémio-Surveillance en Pathologie Equine (RESPE, the French epidemiological network for equine diseases) is a network for epidemio-surveillance of major equine diseases based around sentry veterinarians in France., Objective: The aim of this study was to evaluate the contribution of RESPE to efficient surveillance of equine influenza virus (EIV) in France., Study Design: Retrospective cross-sectional study., Methods: From November 2005 to October 2010, epidemiological and phylogenetic studies were performed on 1426 nasopharyngeal swabs received at the Frank Duncombe Laboratory. Detection was performed by real-time reverse transcription polymerase chain reaction using original primers and probes designed in the matrix protein gene. Phylogenetic analysis was carried out on the HA1 part of haemagglutinin gene amplified from 47 positive-testing samples. Epidemiological information was provided with the majority of samples submitted through RESPE., Results: Of the 920 samples submitted by RESPE-associated veterinarians, 121 (13.1%) from 42 premises were positive for EIV, compared to 26 (5.1%) of the 607 samples received from non-RESPE associated veterinarians. The most extensive outbreak was observed between February and May 2009, affecting 70 horses on 23 premises, 15 of which were managed by RESPE-associated veterinarians. All strains belonged to the American lineage, Florida sublineage, Clade 1 and Clade 2. Clade 1 was identified only during the Grosbois episode., Conclusion: RESPE improved detection of EIV in France, enabled characterisation of the virus strains, yielded valuable information relating to the epidemiology of the disease and identified vaccine breakdown., Potential Relevance: Implementation of a similar surveillance network in other countries may reduce the economic losses associated with outbreaks of EIV., (© 2013 EVJ Ltd.)

Equid herpesvirus 1 (EHV-1)-associated myeloencephalopathy (EHM) is a disease affecting the central nervous system of horses. Despite the constantly increasing interest about this syndrome, epidemiological data are limited especially when related to the description of large outbreaks. The aim of this article is to describe clinical, virological and molecular data obtained throughout a severe outbreak of EHM, with emphasis on laboratory diagnostic methods. The epidemic disease concerned a riding school in France where 7/66 horses aged 12-22 years developed signs of neurological disease in July 2009. Diagnosis of EHM was supported by EHV-1 detection using both real-time PCR and virus culture, and SNP-PCR test for viral strain characterization. EHM morbidity was 10.6% (7/66), mortality was 7.5% (5/66) and case fatality rate was 71.4% (5/7). Clinical presentation of the disease was characterized by the fact that fever was systematically present within 2 days before the severe neurological signs were noted. EHV-1 was detected by PCR in each available blood and nasal swab samples. Neuropathogenic strain only (G(2254) ) was isolated during the current outbreak; C(t) values, used as an indicative level of the viral load, ranged 26.0-37.0 among the six sampled horses. The amount of virus in biological samples was not systematically related to the intensity of the clinical signs being observed. In conclusion, this article described a severe outbreak of EHM while limited in time and restricted to one premise. Molecular data strongly suggested taking into account any low viral load as being a potential risk factor for neurological manifestations., (© 2011 Blackwell Verlag GmbH.)

Reasons for Performing Study: Surfactant protein D (SP-D), mainly synthesised by alveolar type II cells and nonciliated bronchiolar cells, is one important component of innate pulmonary immunity. In man, circulating concentrations of SP-D are routinely used as biomarkers for pulmonary injury. To date, serum SP-D levels have only been investigated in horses in an experimental model of bacterial airway infection., Objectives: To compare serum SP-D concentrations at rest and after exercise in horses with and without inflammatory airway disease (IAD)., Methods: Venous blood samples were collected from 42 Standardbred racehorses at rest and 60 min after performing a standardised treadmill exercise test. Tracheal wash and bronchoalveolar lavage fluid (BALF) samples were collected after exercise. Based on BALF cytology, 22 horses were defined as IAD-affected and 20 classified as controls. Serum SP-D concentrations were assessed using a commercially available ELISA kit and statistically compared between groups of horses and sampling times., Results: Serum concentrations of SP-D in IAD-affected horses were significantly higher than those of control horses, both at rest and after exercise. Within the IAD-affected group, no significant correlation was found between serum SP-D concentrations and BALF cytology. Within each group of horses (IAD and control), no significant influence of exercise was found on serum SP-D levels., Conclusions: This is the first study determining serum SP-D concentrations in a noninfectious, naturally occurring form of lower airway inflammation in horses. The results highlight that IAD is associated with a detectable, though moderate, increase of circulating SP-D levels., Potential Relevance: Serum concentration of surfactant protein D could represent a potentially valuable and readily accessible blood biomarker of equine lower airway inflammation., (© 2011 EVJ Ltd.)

Reasons for Performing Study: Dorsal displacement of the soft palate (DDSP) is one of the most common obstructive conditions of the upper respiratory tract in the racehorse. This condition has a complex aetiology which may be caused or exacerbated by pharyngeal inflammation. Additionally, lower respiratory airway diseases may be associated with DDSP thereby contributing to exercise intolerance in these horses., Objective: The aim of this study was to measure physiological variables during a standardised exercise test and to assess the prevalence and consequences of lower respiratory airway disease in horses with DDSP., Methods: A total of 46 horses were included in this study: 22 in the control and 24 in the DDSP groups. All horses performed a SET with measurement of heart rate (HR) and blood lactate concentration. One hour post exercise, respiratory samples were collected for cytological and bacteriological analysis., Results: During exercise, the DDSP group had higher blood lactate concentration than the control group. According to BAL results, 50 and 63% of control and DDSP group horses, respectively, had evidence of inflammatory airway disease (IAD). In the DDSP group, 42% of horses had a syndrome of tracheal inflammation (STI) with 71% of this group having bacteria isolated at >10(5) CFU/ml., Conclusions: Horses with DDSP showed evidence of a high prevalence of IAD and STI with an associated positive bacteriology in 55% of the cases. Even if DDSP is treated by surgery, the authors' recommendation would be to investigate the possibility of lower respiratory airway problems which may also be impacting the horse's performance and/or surgery efficiency., (© 2010 EVJ Ltd.)

Reasons for Performing Study: The vast majority of equine arteritis virus (EAV) infections are inapparent or relatively mild, but may occasionally cause outbreaks of equine viral arteritis. The event observed in France during the summer of 2007 was the most important seen in the country, with mortality and disruption of economic activity., Objectives: To describe the different stages seen during the outbreak and to show how molecular tools were used for both the detection and management of the crisis., Methods: EAV detection was performed by real-time reverse transcription-polymerase chain reaction (RT-PCR) in blood, nasal swabs, semen or organ samples. Characterisation of EAV strains was performed by sequencing the ORF5 fragment., Results: The outbreak affected 18 premises in 5 counties in western France, which represented the index, 8 primary and 9 secondary premises. Artificial insemination in draught horses was responsible for the virus spread. Eight mortality cases were observed, including one fetus, 5 young foals and 2 mature horses. Forty-three individuals had positive results by real-time RT-PCR. The range of measured cycle threshold (Ct) values varied from 19.8 to 40.4 depending on the biological samples. Phylogenetic analysis revealed that the 33 isolated strains all clustered within the EU-2 subgroup., Conclusions: The mortality rate attests to the virulence of the strain involved in this outbreak. Real-time RT-PCR was used for the first time in order to follow-up an epidemic disease in horses., Potential Relevance: The early detection of 3 signals with high Ct values attest the importance of taking low signals into account in field conditions., (© 2010 EVJ Ltd.)

The objectives of this study were to determine the prevalence of sub-clinical diseases in poorly-performing Standardbred horses, compare their physiological response to exercise with control horses, and identify predictive parameters of poor-performance. Fifty horses underwent thorough clinical and ancillary examinations, including haematological and biochemical evaluation, Doppler echocardiography, standardised exercise tests (SETs) on both treadmill and racetrack, treadmill video-endoscopy and collection of respiratory fluids. Most of the poorly-performing horses exhibited many concomitant diseases. The most frequently diagnosed problems involved the lower and upper respiratory tract and the musculoskeletal system. Poor-performers had lower speeds at a blood lactate (LA) concentration of 4mmol/L (V(LA4)) and a heart rate (HR) of 200bpm (V(200)) on treadmill and racetrack, as well as lower values for haematological parameters, plasma angiotensin-converting enzyme and antioxidants, compared to control horses. Problems of the respiratory system were the most frequently diagnosed sub-clinical diseases affecting performance. SETs, together with some blood markers, may be useful as a non-specific diagnostic tool for early detection of diseases that may affect performance., (Copyright 2009 Elsevier Ltd. All rights reserved.)

Anaplasma phagocytophilum is the agent of pasture fever or tick-borne fever, a disease of ruminants and humans in the United States and in Europe. Although several hundred cases have been suspected to occur in cattle in France, none has yet been microbiologically confirmed. We report the first identification of A. phagocytophilum 16S RNA gene sequence in a case of TBF in France. This indicates that the diagnosis of tick-borne fever should be also evoked in cattle exposed to Ixodes ticks in France.

Anaplasmosis is caused by the bacterium Anaplasma phagocytophilum and transmitted by Ixodes spp. ticks. According to some reports the disease can be introduced into disease-free zones by migrating birds. The purpose of this study was to evaluate the seroprevalence of A. phagocytophilum in horses in the Camargue. Data concerning 424 horses were gathered and the sera were tested for A. phagocytophilum and for piroplasmoses using an enzyme-linked immunosorbent assay and a complement fixation test, respectively. The seroprevalence rates were 11.3 % for A. phagocytophilum, 64.4 % for Theileria equi and 19.7% for Babesia caballi. Stallions were less likely to produce antibodies against A. phagocytophilumthan were females or geldings (odds ratio [OR] = 0.3; p = 0.021). The presence of swallows increased the risk of infections in stables (OR = 5.18; p = 0.011). Spatial analysis showed the existence of groups of infected stables along canals and rivers (p = 0.008). These results suggest an emergence of A. phagocytophilum in the Camargue.

Neospora caninum, an apicomplexan protozoan parasite, is recognized as a major cause of abortion in cattle while limited information is presently available on association between equine Neospora infections and abortions. The aim of the present study was to document prevalence of antibodies against Neospora sp. in aborted mares as a clue to the role of N. caninum in mare reproductive failure in Normandy, France. Using an agglutination test, the number of animals with elevated (>80) anti-Neospora sp. antibody titer was higher in a group of 54 aborted mares than in randomly chosen groups of 45 mares and 76 horses sampled for equine arteritis virus and Fasciola hepatica antibodies, respectively (P<0.001). N. caninum DNA was found in 3/91 fetal brains, 2/77 fetal hearts, and 1/1 placenta, and present in both brains and hearts of two fetuses. In 13 cases for which both mare serum and fetus were available, no fetal N. caninum amplification product was present while a large variation of maternal antibody titers was found. Data prompt at additional surveys of association between equine reproductive failure and Neospora sp. infection.

Sarcocystis neurona is considered a leading cause of equine protozoal myeloencephalitis (EPM), a common infectious neurological disease in horses in the Americas. EPM-like cases associated with S. neurona peptide reactive antibodies in Western blots were recently described in Normandy, France. In this report, antibodies reacting with S. neurona merozoites were detected using an agglutination assay at titers ranging from 50 to 500 in sera from 18/50 healthy horses from two farms with a previous EPM-like case. Higher values were found in older animals. Four out of six horses which traveled or stayed in the US exhibited titers over 50, a higher figure than in the group which did not travel out of France or stayed in an other European country. No correlation was found between anti-S. neurona and anti-Neospora sp. antibody titers. Data prompt further study of significance of anti-S. neurona antibodies in clinically healthy or diseased European horses, and identification of putative immunizing parasite(s) and their host(s).

For over two centuries, Borna disease (BD) has been described as a sporadically occurring infectious meningoencephalomyelitis affecting horses and sheep in Central Europe. Over the last decade, the BD epidemiology has been discussed. Firstly, its geographical distribution seems larger than what was previously thought. Secondly, the disease can affect a large number of warm-blooded animal species, including humans. The aetiological agent is the Boma disease virus (BDV), an enveloped, nonsegmented negative-stranded RNA virus classified in the new virus family Bornaviridae (Mononegavirales order). It can induce severe clinical signs of encephalitis with striking behavioural disturbances and may cause death. BDV genome has recently been detected in France in the blood and brain of several animal species (horses, bovines, foxes).

Neospora caninum is considered one of the major causes of abortion in cattle in most parts of the world. In this study, the role of N. caninum was investigated in groups of aborted cattle and dairy herds from the west of France. Good correlation was found between parasite DNA detection in fetuses and serologic statuses of dams. In groups with documented abortion status and no antibodies to other pathogens, 17-45% of aborted animals were seropositive for N. caninum, and significant relationship between prevalence of Neospora antibodies and frequency of abortions was found. Neospora-associated abortions were observed all the year round, with a peak in summer. Higher ratios of seropositive abortions were found before the 6th month of gestation. In 12 herds studied in the field, serologic prevalence ranged 6-47%. No difference in age was found between seropositive and seronegative cows. Results indicate that N. caninum is an important and stable cause of abortion in cattle in France.