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Weaning is a development stage that brings maternal independence, change of management and feeding, leading to immune deficit. The objective of this study was to evaluate the hematological and biochemical parameters of foals in weaning phase after intravenous administration of hyperimmune plasma (1 mL/Kg) in low dose. Ten foal weaned from the Mangalarga Machador breed were used, being divided in control (GC; n=5) and treated group (GT; n=5). The results obtained show that hematological and biochemical parameters of foals that received low doses of hyperimmune plasma were within the reference range for the equine species.

The objective of this study was to evaluate the testicular changes and detect the presence of Leishmania sp. in the testicles and semen of dogs with Visceral Leishmaniasis (VL). The animals were obtained from the Zoonoses Control Department of Teresina, PI, and taken to the kennel of the Agricultural Sciences Center of the Federal University of Piauí, where they remained were maintained for two months and subsequently euthanized for testicles removal. Semen samples were collected from 12 dogs, 06 positive and 06 negative for VL. The following diagnostic techniques readouts were assessed for the sampled animals: testosterone dosage, immunohistochemistry (IMH), histopathology of the slides containing the testicular material, and seminal evaluation by polymerase chain reaction (PCR). Testosterone values remained within the normal range for the canine specie and did not differ statistically among the experimental groups but displayed lower serum concentrations than those of the control group. All the testicular and semen samples from the dogs were negative for VL as determined by techniques IMH and PCR, respectively. The results of testicle histopathology revealed the presence of several lesions with statistical difference among the experimental groups. Parasitized dogs with VL have testicular lesions that may compromise the reproductive efficiency of these animals. O objetivo deste estudo foi avaliar as alterações testiculares e detectar a presença de Leishmania sp. nos testículos e sêmen de cães com leishmaniose visceral (LV). Os animais foram obtidos da Gerência de Controle de Zoonoses de Teresina, PI, e levados ao canil do Centro de Ciências Agrárias da Universidade Federal do Piauí, onde permaneceram por dois meses e posteriormente foram submetidos à eutanásia para a remoção dos testículos. As amostras de sêmen foram coletadas de 12 cães, sendo 06 positivos e 06 negativos para LV. Nas amostras dos animais, foram realizadas as seguintes técnicas de diagnóstico: dosagem de testosterona, imunohistoquímica (IMH), histopatologia das lâminas contendo o material testicular e avaliação seminal por reação em cadeia pela polimerase (PCR). Valores de testosterona permaneceram dentro do intervalo normal para a espécie canina, não diferindo estatisticamente entre os grupos experimentais, porém apresentando concentrações séricas mais baixas do que o grupo controle. Todas as amostras testiculares e de sêmen dos cães foram negativas para LV, conforme determinado pelas técnicas IMH e PCR, respectivamente. Os resultados da histopatologia dos testículos revelaram a presença de várias lesões com diferença estatística entre os grupos experimentais. Os cães parasitados com LV apresentam lesões testiculares que podem comprometer a eficiência reprodutiva desses animais.

Hyperactivation of tubular cells contributes for the progression of kidney lesions. The exacerbated expression of immunological proteins and ribosomal DNA (rDNA) transcriptional activity are observed in tubular cells. This intensified expression results in more prominent hypertrophic changes and is often accompanied by increased expression of factors involved in different phases of ribosomal biosynthesis, such as the nucleolar organizer regions (NOR). The aim of this study was to evaluate whether there is an association between NOR proteins, renal impairment, and clinical status in Leishmania-infected dogs (CanL). Forty-five dogs with CanL and six uninfected controls were assessed in this study. PCR was performed to detect parasites' nucleic acids in kidney. Histopathological analyses were performed in kidney fragments, and NOR was detected by Ag stain (AgNOR). Leishmania-infected dogs showed more intense inflammation and collagen deposition compared with uninfected controls. Biochemical alterations were observed only in Leishmania-infected dogs. AgNORs per cell were significantly higher in clinically affected dogs and higher histopathological lesion score was observed in Leishmania-infected dogs. Positive correlations between number of NORs per cell in medullary region and histopathological lesion score were observed. Furthermore, AgNOR expression, intensity of renal lesions, and clinical sigs was associated in Leishmania-infected dogs. We propose that the detection of AgNOR proteins could be used to better estimate the kidney tubular damage at the time of examination in Leishmania-infected dogs as a marker to estimate renal impairment in dogs with CanL.

The visceral establishment of Leishmania infantum in dogs may result in kidney and bladder tissue injury, with L. infantum ending up in urine. This study therefore aimed at investigating the presence of Leishmania sp. in urinary sediments, and correlating the results with those from renal and bladder serum biochemistry and histopathology. Thirty dogs with negative Nested-Polymerase Chain Reaction (PCR) for E. canis were used in the experiment, and were divided into three groups: control group (10 dogs), neither leishmaniasis nor clinical changes; group I (15 dogs), leishmaniasis but no Leishmania sp. in urine; and group II (5 dogs), leishmaniasis, as well as Leishmania sp. in urine. All animals were submitted to clinical, serological, and parasitological diagnosis for leishmaniasis, biochemical exams, and kidney and bladder histopathology. The parasite was also detected in the bladder imprint of one group II dog. Group II dogs presented with very low albumin concentrations, low albumin/globulin ratios, and kidney and bladder lesions. In the kidneys, hydropic degeneration, thickened Bowman's capsule, and thickening of the tubular capsule were detected in all dogs with positive urinary sediment. However, no significant difference in these renal changes was observed between groups. The intensity and distribution of bladder inflammatory infiltrates were significantly (p-value < 0.05, Kruskal-Wallis’ and Dunn’s tests) higher in group II dogs, compared with those of the other groups. The presence of Leishmania sp. in the urine of infected dogs appeared to be related to low serum albumin concentrations and more severe bladder lesions. O estabelecimento visceral de Leishmania infantum em cães pode resultar em lesões nos tecidos dos rins e da bexiga, favorecendo a chegando do parasito até a urina. Portanto, este estudo teve como objetivo investigar a presença de Leishmania sp. em sedimentos urinários e correlacionar os resultados com os achados de quantificações bioquímicas séricas e histopatologia de rim e bexiga. Trinta cães com Nested-Reação em Cadeia da Polimerase (PCR) negativa para E. canis foram utilizados no experimento e foram divididos em três grupos: grupo controle (10 cães), negativos para leishmaniose e sem alterações clínicas; grupo I (15 cães), com leishmaniose, mas sem Leishmania sp. na urina; e grupo II (5 cães), com leishmaniose e com Leishmania sp. na urina. Todos os animais foram submetidos a diagnóstico clínico, sorológico e parasitológico para leishmaniose, exames bioquímicos e histopatologia de rim e bexiga. O parasito foi detectado no imprimt de bexiga de um cão do grupo II. Os cães do grupo II apresentaram concentrações muito baixas de albumina, baixa relação albumina/globulina e lesões nos rins e na bexiga. Nos rins, foram detectadas degeneração hidrópica, espessamento da cápsula de Bowman e espessamento da cápsula tubular, em todos os cães com sedimento urinário positivo. No entanto, nenhuma diferença significativa nessas alterações renais foi observada entre os grupos. A intensidade e a distribuição dos infiltrados inflamatórios da bexiga foram significativamente (p-valor < 0,05, testes de Kruskal-Wallis e Dunn) maiores nos cães do grupo II, em comparação com a dos outros grupos. A presença de Leishmania sp. na urina de cães infectados parece estar relacionada a baixa concentração sérica de albumina e a lesões mais graves na bexiga.

Among the diseases that affect the reproductive system of domestic animals, brucellosis in the sheep species is important because it generates significant economic losses to sheep rearing. Thus, it is a threat to the growth and productivity of sheep herds. In the face of this problem, the objective of the present research was to identify the prevalence of ovine brucellosis in herds in municipalities of the Teresina, Piauí, Brazil microregion by using the agar gel immunodiffusion assay (AGID) and indirect enzyme-linked immunosorbent assay (ELISA) serological tests. Fourteen municipalities were included in the research. Blood samples were collected from 521 pubescent animals by puncturing the jugular vein. After collection, the samples were submitted to the serological techniques, AGID and indirect ELISA, to detect anti B. ovis antibody. Of the 521 samples submitted to the AGIDtest, 23 (4.41%) were sera reagent and 498 (95.58%) negative. The indirect ELISA tests, 24 (4.61%) suspect samples and 497 (95.39%) negative samples were obtained, and there were no reagent animals in this test, only suspect. The seroprevalence of ovine brucellosis in the Teresina, Piauí microregion was 4.41%. Thus, it is possible to identify sheep with reagent serology to infection by B. ovis, that is present in municipalities in the state of Piauí, Brazil. Furthermore, AGIDwas shown to be more sensitive in detecting animals that had had contact with the etiological agent of the disease.

El estudio tuvo como objetivo identificar y describir lesiones intestinales ocasionadas por helmintos en jabutis (Chelonoidis carbonarius y Chelonoidis denticulatus) criados en cautiverio en el Parque Zoobotánico de Teresina, estado de Piauí, Brasil. La evaluación parasitológica de 142 de estas tortugas reveló que todas estaban parasitados por helmintos (ascarídeos y estrongilideos), que fueron identificados como Atractis thapari y Chapiniella variabilis por medio de microscopio de luz y microscopio electrónico. Los 12 animales más parasitados (seis de cada especie) fueron eutanasiados y muestras de intestino delgado y grueso fueron evaluadas por histopatología. Macroscópicamente, todos los intestinos, tanto delgado como grueso, presentaban hiperemia. Microscópicamente, en el intestino delgado se observó hiperemia (12/12), hiperplasia difusa de células caliciformes (8/12) y edema de submucosa (1/12). En el intestino grueso se observó hiperemia, variando entre discreta a intensa (12/12) y enteritis transmural granulomatosa focalmente extensa e intensa (1/12)., The aim of this study was to identify and describe intestinal lesions caused by helminths in red-footed tortoise (Chelonoidis carbonarius) and yellow-footed tortoise (Chelonoidis denticulatus) reared in captivity in the Zoo and Botanical Park of Teresina, Piauí State, Brazil. The parasitological evaluation of 142 of these tortoises revealed that all were parasitized by helminths (ascarids and strongyles), which were identified as Atractis thapari and Chapiniella variabilis by light and electron microscopy. The 12 most parasitized tortoises (six per species) were euthanized, and samples of small and large intestine were evaluated by histopathology. Macroscopically, all small and large intestines had hyperaemia. Microscopically, hyperaemia (12/12), diffuse goblet cell hyperplasia (8/12) and submucosa oedema (1/12) were observed in the small intestine. Hyperaemia was observed in the large intestine, varying from discrete to intense (12/12) and focally extensive and severe transmural granulomatous enteritis (1/12).

RESUMO A brucelose na espécie ovina tem recebido destaque, uma vez que se trata de uma enfermidade que acomete o sistema reprodutivo dos animais, provocando sério comprometimento no setor produtivo. Dessa forma, objetivou-se a avaliação de três métodos para o diagnóstico da brucelose ovina: o ensaio imunoenzimático indireto (ELISAi), a técnica imunodifusão em gel de ágar (IDGA) e a reação em cadeia da polimerase (PCR). Para tanto, utilizaram-se 211 amostras de sangue de ovinos oriundos de propriedades de nove municípios da microrregião homogênea de Teresina, Piauí. As 211 amostras de sangue foram submetidas aos testes sorológicos e à PCR, visando detectar anticorpos anti-B. ovis e DNA de Brucella ovis, respectivamente. Foram obtidos resultados positivos nos testes sorológicos, sendo 36 (17,06%) positivos no teste IDGA e sete (3,31%) positivos no teste ELISAi, contudo não houve resultados positivos na técnica de PCR. Dos métodos de diagnóstico utilizados neste estudo, o teste IDGA foi o que apresentou melhor desempenho na detecção de animais reagentes, quando comparado ao teste ELISAi e à PCR em amostras de sangue, e o percentual de animais soropositivos sugere uma ampla distribuição de ovinos infectados por Brucella ovis na região em estudo, o que pode causar prejuízos aos produtores.

Visceral leishmaniasis is caused by Leishmania chagasi in Brazil. It is a disease that is decimating the canine population in rural and urban areas and has great health public importance because it is a zoonosis that has major problems and consequences for man. The emergence of human cases of visceral leishmanias is in the city of Valencia Piaui led to this investigation of the incidence of the disease in dogs. We conducted clinical and serological by Immuno Fluorescence Assay (IFA) of 190 dogs. The total reactive serum of animals, 102 were in the New Horizon neighborhood and 65 in Valencinha. 50 animals were selected with the greatest number of clinical signs, with varying antibody titer1:40 to1: 320 and the negative animals. Confirmation of the presence of Leishmania in selected animals was through the puncture and bone marrow aspirate of popliteal lymph node. The collected material was seeded in NNN culture medium enriched with Schneider's. After seeding, it is proceeded three readings every five days, and observed the presence of Leishmania promastigotes in 16 samples. The Nunes Filho et al. 443 PubVet Maringa, v. 9, n. 10, p. 442-447, Out., 2015 findings confirmed the Leishmania infection in animals of the neighborhoods under study, which characterizes it, in this region, given the presence of foxes in the woods and peridomestics and fly vectors, closes the cycle of this wild and urban zoonosis. Hence the need to raise awareness about the risks of epidemics and alert the authorities about the emergency measures: such as periodic fumigation residences, animal sacrifice demonstrably infected, treatment of sick people and repetition of epidemiological surveys.

A dificuldade de manutenção do rebanho em condições sanitárias adequada compromete a eficiência da criação de caprinos, principalmente em relação ao controle de endoparasitas. O objetivo com este trabalho foi avaliar a sensibilidade de matrizes da raça Anglonubiana a nematoides gastrintestinais, considerando as cabras estratificadas por estágio fisiológico (lactantes e não lactantes) dentro de três classes de idade. Utilizou-se as características: Ovos por grama de fezes (OPG), Grau de anemia (indicado pelo método Famacha©), Peso e Escore da condição corporal e porcentagem de coletas de fezes cujo valor do OPG foi igual a Zero, variável utilizada para demonstrar a resposta ao antihelmintico, disponibilizadas pelo banco de dados dessa raça na UFPI. Os dados são referentes ao período de janeiro de 2009 a dezembro de 2011. As cabras em lactação apresentaram maior valor médio de OPG, maior grau de anemia, menor escore corporal e menor quantidade de coleta de fezes com valor de OPG zero, que as cabras não lactantes, independentemente da classe de idade considerada. Assim, a lactação aumenta a sensibilidade a endoparasitismo em matrizes da raça Anglonubiana. A elevação do OPG tende a se mostrar associada ao maior grau de anemia determinado pelo método Famacha©, que levam a redução da condição corporal. The difficulty of maintaining adequate sanitary herd health conditions compromises the efficiency of goat breeding, especially in relation to parasite control. The goal with this study was to evaluate the sensibility of female Anglo-Nubiangoats to gastrointestinal nematodes. The does were evaluated stratified by physiological stage (lactating and non-lactating) in three age classes. The following characteristics were used: eggs per gram of feces (EPG), degree of anemia (according to the Famacha© method), weight and body condition score and percentage of fecal samples with EPG value equal to Zero, variable used to demonstrate the response to anthelmintic, available in the breed database at UFPI. Data is available for the period from January 2009 to December 2011. Lactating female goats had higher EPG mean value, higher degree of anemia, lower body condition score and fewer feces sampled with zero EPG value, when compared to non-lactating goats, regardless of the age group considered. Therefore, lactation increases sensitivity to endoparasitism in female Anglo-Nubian goats. Elevation of EPG tends to appear associated with an increased degree of anemia determined by the Famacha© method, leading to a reduction of body condition.

Leishmaniasis is a complex of parasitic protozoan diseases caused by more than 20 different species of parasites from Leishmania genus. Conventional treatments are high costly, and promote a sort of side effects. Besides, protozoan resistance to treatments has been reported. Natural products have been investigated as a source of new therapeutic alternatives, not only acting directly against the parasite but also being able to synergistically act on the host immune system in order to control parasitemia. Gallic acid (GA) and ellagic acid (EA) are plant-derived phenolic compounds which are able to induce antiinflammatory, gastroprotective, and anticarcinogenic activities. Therefore, the antileishmania, cytotoxic, and immunomodulatory activities of GA and EA were evaluated in this study. Both GA and EA were able to inhibit the growth of Leishmania major promastigotes (effective concentration (EC50) values 16.4 and 9.8 μg/mL, respectively). The cytotoxicity against BALB/c murine macrophages for GA and EA was also assessed (CC50 values 126.6 and 23.8 μg/mL, respectively). Interestingly, GA and EA also significantly reduced the infection and infectivity of macrophages infected by L. major (EC50 values 5.0 and 0.9 μg/mL, respectively), with selectivity index higher than 20. Furthermore, both GA and EA induced high immunomodulatory activity evidenced by the increase of phagocytic capability, lysosomal volume, nitrite release, and intracellular calcium [Ca2+i] in macrophages. Further investigations are reinforced in order to evaluate the therapeutic effects of GA and EA in in vivo experimental infection model of leishmaniasis.

Made available in DSpace on 2018-11-26T17:34:47Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-01-01. Added 1 bitstream(s) on 2019-10-09T18:26:48Z : No. of bitstreams: 1 S0036-46652017005000221.pdf: 695746 bytes, checksum: 174214c15f01ea10a7c9efcf117fd31d (MD5) Dogs are considered the main reservoir of Leishmania infantum. This protozoan causes visceral leishmaniasis (VL), an uncontrolled urban zoonosis in Brazil. Serological tests and polymerase chain reaction (PCR) on peripheral blood were performed to identify infected dogs in scenarios of higher and lower prevalence of the disease (Teresina and Vitoria). One-hundred infected and 57 non-infected animals from Teresina and 100 non-infected animals from Vitoria were studied. Animal selection was not dependent on previous serology. The sensitivity (Teresina) and specificity (Teresina and Vitoria) were as follows: indirect antibody fluorescence (IFAT) cut-off of 1:40 (IFAT 1:40): 96%, 18%, and 76%; IFAT 1:80: 90%, 33%, and 93%; direct agglutination test (DAT): 96%, 33%, and 98%; fast agglutination screening test (FAST): 93%, 68%, and 100%; immunochromatographic assay with a recombinant rK39 antigen (rK39): 88%, 74%, and 98%; enzyme linked immunosorbent assay (ELISA): 91%, 79%, and 98%; rapid dual-path platform test (TR DPP (R)): 98%, 60%, and 98%; and blood PCR: 29%, 93%, and 97%, respectively. In the high transmission area, none of the tests adequately discriminated L. infantum-infected from non-infected dogs. However, in the high transmission city, the area under the receiver operating characteristic (ROC) curve of FAST, DAT, ICrK39, ELISA and TR DPP (R) was high. Univ Fed Piaui, Ctr Ciencias Agr, Programa Posgrad Ciencia Anim, Teresina, Piaui, Brazil Koninklijk Inst Tropen, Biomed Res, Amsterdam, Netherlands Univ Estadual Paulista, Inst Biol & Biomed, Dept Parasitol, Botucatu, SP, Brazil Univ Fed Piaui, Inst Doencas Trop Natan Portella, Lab Leishmanioses, Teresina, Piaui, Brazil Univ Estadual Paulista, Inst Biol & Biomed, Dept Parasitol, Botucatu, SP, Brazil

Feline leishmaniasis has been reported in various parts of the world in recent years, occurring mainly in areas where zoo notic visceral leishmaniasis (VL) is endemic. The purpose of this study was to assess the occurrence of natural infection by Leishmania spp. in domestic cats (Felis catus) in the municipality of Teresina, Piauí state, Brazil, an endemic area of VL in Brazil. The prevalence of infection by Leishmania spp. in the population under study was 4% (3/83) in the enzyme-linked immunosorbent assay (ELISA) and 4% (3/83) by smear observation and isolation in a culture medium, using popliteal lymphnode sample. Only one of the three infected cats was positive for ELISA, also being positive for feline immunodefi ciency virus. In the haematologic parameters, normocytic normochromic anaemia was the most common change, being present in the three infected animals. In the biochemical measurements also were observed alterations in infected animals. The Leishmania spp. strains isolated from the culture medium were characterized as L. infantum. The presence of L. infantum infection in cats in the city of Teresina, an area endemic for VL, suggests the possible involvement of these animals in the epidemiological chain of L. infantum in high-transmission areas. A leishmaniose felina tem sido relatada em várias partes do mundo nos últimos anos, ocorrendo principalmente em áreas onde a leishmaniose visceral zoonótica (LV) é endêmica. O objetivo deste estudo foi avaliar a ocorrência de infecção natural por Leishmania spp. em gatos domésticos (Felis catus) no município de Teresina, Piauí, Brasil, área endêmica de LV em Brasil. A prevalência da infecção por Leishmania spp. na população em estudo foi de 4% (3/83) na ensaio imunossorvente (ELISA) e 4% (3/83) por observação de esfregaço e isolamento em meio de cultura, usando poplíteo amostra de linfonodo. Apenas um dos três gatos infectados foi positivo para ELISA, sendo também positivo para o vírus da imunodeficiência felina. Nos parâmetros hematológicos, a anemia normocítica normocrômica foi a alteração mais comum, sendo presente nos três animais infectados. Nas medidas bioquímicas também foram observadas alterações em animais. A Leishmania spp. cepas isoladas do meio de cultura foram caracterizadas como L. infantum. A presença de infecção por L. infantum em gatos na cidade de Teresina, área endêmica para LV, sugere o possível envolvimento desses animais da cadeia epidemiológica de L. infantum em áreas de alta transmissão.

Canine visceral leishmaniasis (CVL) is difficult to diagnosis, mainly due to the presence of asymptomatic animals, the diversity of clinical symptoms and the difficulty in obtaining diagnostic evidence of high sensitivity and specificity. The purpose of this study was to diagnose CVL in urinary sediment of 70 dogs of different breeds, sexes and ages from the veterinary hospital of the Federal University of Piauí and Zoonosis Control Center of Teresina, Brazil. The serological tests were TR DPP® for CVL and enzyme-linked immunosorbent assay (ELISA) for CVL, parasitological exams of bone marrow and lymph nodes and urine sediment cultures. Leishmania was detected in the bone marrow and/or lymph node of 61.0% of the animals (43/70), and urine sediment culture was positive in 9.30% (4/43) of these animals. In the serological exams, 70.0% (49/70) were reactive using the DPP and 78.2% (55/70) were reactive using ELISA. The goal of this study was to diagnose the presence of L. (infantum) chagasi in a culture of urinary sediment. A leishmaniose visceral canina (LVC) é uma doença de difícil diagnóstico. Principalmente devido à presença de animais assintomáticos, a diversidade da sintomatologia clínica apresentada e também pela dificuldade em se obter uma prova diagnóstica que reúna alta sensibilidade e especificidade. O objetivo deste trabalho foi relatar a presença de L. (infantum) chagasi em meio de cultura, utilizando-se sedimento urinário. Foram utilizados neste experimento, 70 cães provenientes do Hospital Veterinário Universitário da Universidade Federal do Piauí e do Centro de Controle de Zoonoses de Teresina, com raça, sexo e idade variada. Foram realizados exames sorológicos: TR DPP® Leishmaniose Visceral Canina (DPP) e Ensaio Imunoenzimático Leishmaniose Visceral Canina (ELISA), exames parasitológicos de amostras de medula e/ou linfonodo e cultura de sedimento urinário. Em 61,0% (43/70) dos animais estudados, observou-se presença de Leishmania em medula e/ou linfonodo, e destes 9,30% (4/43) foram positivos na cultura de sedimento urinário. Nos exames sorológicos, 70,0% (49/70) dos animais apresentavam-se reativos no DPP e 78,2% (55/70) no ELISA. Pode-se concluir, neste estudo, que é possível diagnosticar a LVC por meio da cultura de sedimento urinário.

This study investigated the sero-conversion period in which dogs from endemic areas test positive for visceral leishmaniasis (VL) as well as the early post-infection period in which renal alterations are observed. Dogs that were initially negative for Canine Visceral Leishmaniasis (CVL) were clinically evaluated every three months by serological, parasitological and biochemical tests until sero-conversion was confirmed, and six months later a subsequent evaluation was performed. Samples of kidney tissues were processed and stained with Hematoxylin and Eosin (H&E), Periodic Acid Schiff (PAS) and Masson’s trichrome stain and lesions were classified based on the WHO criteria. Of the 40 dogs that initially tested negative for VL, 25 (62.5%) exhibited positive serological tests during the study period. Of these 25 dogs, 15 (60%) tested positive within three months, five (20%) tested positive within six months and five (20%) tested positive within nine months. The dogs exhibited antibody titers between 1:40 and 1:80 and 72% of the dogs exhibited clinical symptoms. The Leishmania antigen was present in the kidneys of recently infected dogs. We found higher levels of total protein and globulin as well as lower levels of albumin in the infected dogs when compared to the control dogs. Additionally, infected dogs presented levels of urea and creatinine that were higher than those of the uninfected dogs. Glomerulonephritis was detected in some of the dogs examined in this study. These data suggest that in Teresina, the sero-conversion for VL occurs quickly and showed that the infected dogs presented abnormal serum proteins, as well as structural and functional alterations in the kidneys during the early post-infection period. Este estudo investigou o período em que o cão torna-se positivo para leishmaniose visceral (VL) em área endêmica e as alterações renais no período recente pós-infecção. Cães negativos para VL foram avaliados clinicamente a cada três meses por testes sorológicos, parasitológicos e bioquímicos até a soro-conversão e seis meses após. Foram colhidos tecido renal de seis cães, submetidos a processamento de rotina e corados com HE, PAS e Masson e as lesões foram classificadas com base nos critérios da OMS. Dos 40 cães nagativos para VL, 25 (62,5%) apresentaram sorologia positiva durante o estudo. Desses, 15 (60%) tornaram-se positiva nos primeiros três meses, cinco (20%) tornaram-se positivas dentro de seis meses e cinco (20%) tornaram-se positivas dentro de nove meses. Os cães apresentavam títulos de anticorpos entre 1:40 e 1:80, e 72% mostraram sinais clínicos. Antígeno de Leishmania estava presente no rim. Foram encontrados níveis mais elevados de proteína total e globulina, e menores níveis de albumina em cães infectados quando comparados aos controles. Além disso, os cães infectados apresentaram níveis de uréia e creatinina maior do que os cães controles. Glomerulonefrite foi observada em cinco cães. Os resultados sugerem que em Teresina a soro-conversão para VL ocorre rapidamente e os cães apresentam proteínas séricas anormais e alterações na estrutura e função dos rins em um período recente pós-infecção.