Mefenoxam and pyraclostrobin: toxicity and in vitro inhibitory activity against Pythium insidiosum.

The objective of this study is to verify in vitro susceptibility of Pythium insidiosum against the agricultural fungicides mefenoxam and pyraclostrobin and evaluate the toxicity of both compounds. Twenty-one P. insidiosum isolates were tested against mefenoxam and pyraclostrobin using the broth microdilution method. Minimum inhibitory and oomicidal concentrations for both compounds were established. Additionally, scanning electron microscopy was performed on P. insidiosum hyphae treated with the sublethal concentration of each fungicide. The toxicity of the compounds was evaluated in vivo Caenorhabditis elegans model. The concentration to inhibit 100% of P. insidiosum growth ranged from 0·625 to 10 µg ml-1 for mefenoxam and from 0·019 to 5 µg ml-1 for pyraclostrobin. The SEM analysis revealed changes on the surface of the hyphae treated with the fungicides, suggesting possible damage caused by these compounds. There was no evidence of toxicity in vivo models. Mefenoxam and pyraclostrobin did not show toxicity at the doses evaluated and have inhibitory effects on the pathogenic oomycete P. insidiosum. However, further evaluations of their pharmacokinetics and toxicity in different animal species and possible pharmacological interactions are necessary to infer a possible use in the clinical management of pythiosis.

Activity of biogenic silver nanoparticles against isolates of Prototheca species from bovine mastitis.

Prototheca spp. cause numerous infections in a wide variety of species, including treatment-unresponsive mastitis. Thus, the search for an effective therapy is essential. Silver nanoparticles are compounds with high therapeutic potential. This study aimed to evaluate the susceptibility profile and morphological changes in Prototheca spp. treated with biogenic silver nanoparticles (Bio-AgNP). The algaecide activity was evaluated in microplates by microdilution method, resulting in a MIC50 of 30 µg ml-1 and a MIC90 of 60 µg ml-1 . Scanning electron microscopy demonstrated changes in the surface of Prototheca bovis cells following treatment. The algaecide activity of Bio-AgNP suggests a therapeutic potential as a novel approach for the control of Prototheca spp. in bovine mastitis.

Neospora caninum DNA distribution in tissues of gerbils as experimental models of chronic neosporosis / [Distribuição do DNA de Neospora caninum em tecidos de gerbilos como modelos experimentais de neosporose crônica]

Neospora caninum is the main etiologic agent of neosporosis in domestic animals and its pathogenesis comprises two characteristic phases: acute and chronic. Rodents are used as experimental models to mimic acute and chronic bovine neosporosis. In this study, we inoculated a total of 27 female gerbils, with different doses of N. caninum tachyzoites aiming to induce chronic disease. DNA was extracted from different organs of each animal after spontaneous death or euthanasia. Encephalic tissues were submitted to a highly sensitive real time PCR aiming to detect chronically infected animals. All the other samples were submitted to standard PCR. A total of 11 gerbils died due to acute neosporosis, as confirmed by N. caninum DNA detection in organs. 5x103 tachyzoites/mL of N. caninum was the dosage of antigen that can induce chronic infection in gerbils. In the encephalon sections of some animals that showed clinical signs of persistent infection, we found 70% positive for the anterior encephalon section, suggesting this area as preferential for cyst formation. Therefore, we determined the doses of tachyzoites that cause acute or chronic infection and detection of positive tissues, preferably, systemic organs during acute and encephalon in chronic phases.(AU)

Neospora caninum é o principal agente etiológico da neosporose em animais domésticos, e sua patogênese compreende duas fases características: aguda e crônica. Roedores são usados como modelos experimentais para simular neosporose bovina aguda e crônica. Neste estudo, foi inoculado um total de 27 gerbilos, fêmeas, com diferentes doses de taquizoítos de N. caninum, visando induzir doença crônica. O DNA foi extraído de diferentes órgãos de cada animal após a morte espontânea ou a eutanásia. Os tecidos encefálicos foram submetidos à PCR em tempo real de alta sensibilidade para detecção de animais com infecção crônica. Todas as outras amostras foram submetidas à PCR padrão. Um total de 11 gerbilos morreu devido à neosporose aguda, como confirmado pela detecção de DNA de N. caninum nos órgãos. A dosagem de antígeno que pode induzir infecção crônica foi de 5x103 taquizoítos/mL de N. caninum. Em seções do encéfalo de alguns animais, que apresentaram sinais clínicos de infecção persistente, encontraram-se 70% de positividade para a seção do encéfalo anterior, sugerindo essa área como preferencial para a formação de cisto. Assim, foram determinadas,, em gerbilos, as dosagens de taquizoítos capazes de induzir infecção crônica ou aguda, bem como foram detectados tecidos positivos, preferencialmente, em órgãos sistêmicos, na fase aguda, e no encéfalo, na crônica.(AU)

Toxoplasma gondii genotyping from free-range chickens (Gallus gallus domesticus) in a rural area of Rio Grande do Sul, Brazil / [Genotipagem de Toxoplasma gondii em galinhas domésticas em uma área rural do Rio Grande do Sul, Brasil]

Free-range chickens may ingest oocysts of T. gondii present in the environment and consequently harbor virulent strains of this parasite in different tissues, without any clinical signs. Isolation of T. gondii through bioassays on mice and cats from naturally infected chicken tissues has been described in several countries, demonstrating the importance of free-range chickens in the transmission of this parasite. The aim of this study was the genotypic characterization of T. gondii isolates obtained from naturally infected free-range chickens in a rural area of the state of Rio Grande do Sul, Brazil. Brain and heart tissue from 12 chickens seropositive for T. gondii were processed using peptic digestion technique for parasite isolation. From 12 samples subjected to mouse bioassay, nine isolates were obtained. RFLP-PCR genotypic characterization was performed using 11 genetic markers: SAG1, 5'-3'SAG2, alt.SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico. Genetic characterization of the isolates revealed the presence of five atypical genotypes according to ToxoDB (# 11, # 55, # 64, # 140 and # 163). Our results showed a wide genetic diversity of T. gondii in free-range chickens in this region.(AU)

Galinhas criadas ao ar livre podem ingerir oocistos de T. gondii presentes no ambiente e, com isso, albergar cepas virulentas desse parasita em diferentes tecidos, sem sinais clínicos. O isolamento de T. gondii por meio de bioensaios em camundongos e gatos, a partir de tecidos de galinhas naturalmente infectadas, tem sido descrito em vários países. Isso demonstra a importância das galinhas caipiras na epidemiologia desse parasita. O objetivo deste trabalho foi caracterizar genotipicamente isolados de T. gondii obtidos de galinhas caipiras naturalmente infectadas em uma área rural do município de Santa Maria, estado do Rio Grande do Sul, Brasil. Fragmentos de cérebro e de coração, de 12 galinhas soropositivas para T. gondii, foram processados pela técnica de digestão péptica para isolamento do parasita. Das 12 amostras submetidas a bioensaio com camundongos, nove isolados foram obtidos. A caracterização genotípica por RFLP-PCR foi realizada utilizando-se 11 marcadores genéticos: SAG1, 5'-3'SAG2, alt.SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 e Apico e revelou a presença de cinco genótipos atípicos de acordo com o ToxoDB (# 11, # 55, # 64, # 140 e # 163). Os resultados mostraram uma ampla diversidade genética de T. gondii em galinhas caipiras nessa região.(AU)

Moraxella bovis, Moraxella ovis and Moraxella bovoculi: biofilm formation and lysozyme activity.

AIMS: This study aimed to verify the formation of biofilms by Moraxella bovis, Moraxella ovis and Moraxella bovoculi isolates from ruminants. In addition, the lysozyme activity against the isolates of M. bovis, M. ovis and M. bovoculi in free form and in biofilms was determined. METHODS AND RESULTS: In this study, 54 isolates of Moraxella sp. obtained from bovine and ovine clinical samples were evaluated in vitro for capacity of biofilm formation and lysozyme susceptibility in planktonic and sessile cells. In addition, biofilms produced by four Moraxella sp. isolates were visualized under scanning electron microscope (SEM). It was possible to demonstrate, for the first time, the ability to form biofilms by M. ovis and M. bovoculi. The isolates of Moraxella sp. have the capacity to form biofilms in different intensities, varying among weak, moderate and strong. It was verified that the lysozyme shows activity on Moraxella sp. in planktonic form. However, on biofilms there was a reduction in the production, but without impairing its formation, and on consolidated biofilms the lysozyme did not have the capacity to eradicate the preformed biofilms. CONCLUSIONS: This work shows the capacity of biofilm formation by Moraxella sp. of veterinary importance. The lysozyme susceptibility of Moraxella sp. in planktonic form shows that this enzyme has bacteriostatic activity on this micro-organism and it reduced the production of biofilms. SIGNIFICANCE AND IMPACT OF THE STUDY: Based on the results, it is possible to infer that the biofilm formation capacity by Moraxella sp. and the resistance to lysozyme concentrations equal to or greater than the physiological levels of the ruminant tear may be linked not only to the capacity to colonize the conjunctiva, but also to remain in this place even after healing of the lesions, being a reservoir of Moraxella sp. in a herd.

Coinfecções por Leishmania infantum, Neospora caninum e Toxoplasma gondii em cães necropsiados da região central do Rio Grande do Sul, Brasil / Coinfections by Leishmania infantum, Neospora caninum and Toxoplasma gondii in necropsied dogs from the central region of Rio Grande do Sul, Brazil

O objetivo do presente trabalho foi determinar a presença de anticorpos para Leishmania infantum, Neospora caninum e Toxoplasma gondii, por meio da reação de imunofluorescência indireta (RIFI), em cães (n=78) provenientes da região central do Rio Grande do Sul, necropsiados no Hospital Veterinário da Universidade Federal de Santa Maria (UFSM), bem como avaliar os dados epidemiológicos, sazonais e anátomo-histopatológicos. Do total de animais avaliados, 67,9% (53/78) apresentaram soropositividade para ao menos um agente. A ocorrência de anticorpos para L. infantum, N. caninum e T. gondii foi de 33,3 (26/78), 37,1 (29/78) e 43,5% (34/78), respectivamente. Detectaram-se monoinfecções em 9,4% (5/53) para L. infantum, 18,8% (10/53) para N. caninum e 20,7% (11/53) para T. gondii. As coinfecções foram observadas em 27/53 (50,9%) dos animais. As infecções ocorreram independentemente de idade, sexo, procedência ou raça (P>0,05). Não se verificaram lesões anatomo-histopatológicas relacionadas aos agentes pesquisados, caracterizando-os como animais assintomáticos. Os resultados confirmaram a exposição de cães a esses protozoários na região central do RS e, em especial, demonstraram a circulação do agente causador da leishmaniose em uma área considerada indene para a enfermidade.(AU)

The present paper is aimed to determine the presence of antibodies for Leishmania infantum, Neospora caninum and Toxoplasma gondii by indirect immunofluorescence (IIF) in dogs (n=78) from the central region in the state of Rio Grande do Sul necropsied in the Veterinary Hospital from Universidade Federal de Santa Maria (UFSM). The data was evaluated regarding epidemiological, anatomic, and histopathologic findings. Of the total animals evaluated, 67.9% (53/78) showed seropositivity for at least one agent. The occurrence of antibodies to L. infantum, N. caninum and T. gondii was 33.3% (26/78) 37.1% (29/78) and 43.5% (34/78), respectively. The mono infections were detected in 9.4% (5/53) of L. infantum, 18.8% (10/53) for N. caninum and 20.7% (11/53) T. gondii. The coinfections occurred in 50.9% (27/53) of animals. There were not anatomical and histopathological lesions regarding these surveyed agents, characterizing them as subclinical animals. The results confirmed the exposition of dogs to these protozoa in the central region of the RS, highlighting the circulation of the causer agent of leishmaniasis in an area considered harmless for the disease.(AU)

Intra-uterine exposure of horses to Sarcocystis spp. antigens / Exposição intrauterina ao Sarcocystis spp. em equinos

The aim of this study was to examine the intra-uterine exposure to Sarcocystis spp. antigens, determining the number of foals with detectable concentrations of antibodies against these agents in the serum, before colostrum ingestion and collect data about exposure of horses to the parasite. Serum samples were collected from 195 thoroughbred mares and their newborns in two farms from southern Brazil. Parasite specific antibody responses to Sarcocystis antigens were detected using the indirect immunofluorescent antibody test (IFAT) and immunoblot analysis. In 84.1% (159/189) of the pregnant mares and in 7.4% (14/189) of foals we detected antibodies anti-Sarcocystis spp. by IFAT. All samples seropositive from foals were also positive in their respective mares. Serum samples of seropositive foals by IFAT, showed no reactivity on the immunoblot, having as antigens S. neurona merozoites. In conclusion, the intra-uterine exposure to Sarcocystis spp. antigens in horses was demonstrated, with occurrence not only in mares, but also in their foals, before colostrum ingestion these occurrences were reduced.

O objetivo deste estudo foi avaliar a exposição intrauterina ao Sarcocystis spp., para determinar o número de potros que possuem concentrações detectáveis de anticorpos contra esses agentes no soro, antes da ingestão do colostro, por meio da coleta de dados sobre a exposição a esses protozoários nos equinos. Amostras de soro foram coletadas de 195 éguas puro-sangue e seus respectivos potros recém-nascidos, em duas fazendas localizadas na região Sul do Brasil. Os testes utilizados na detecção de anticorpos específicos para o Sarcocystis foram a reação de imunofluorescência indireta (RIFI) e análise por meio de immunoblot. Pela RIFI, em 84,1% (159/189) das éguas e em 7,4% (14/189) dos potros foram detectados anticorpos anti-Sarcocystis spp. Todas as amostras soropositivas dos potros também foram positivas para suas respectivas mães. As amostras de soro dos potros soropositivos na RIFI, não apresentaram reatividade no immunoblot, tendo como antígenos merozoítos de S. neurona. Em conclusão, foi demonstrada a exposição intrauterina de Sarcocystis spp. em equinos, com ocorrência em éguas, porém, em seus respectivos potros, antes da ingestão de colostro a ocorrência foi reduzida.

Investigação de anticorpos contra Sarcocystis neurona e Sarcocystis cruzi em equinos / Investigation of antibodies against Sarcocystis neurona and Sarcocystis cruzi in equines

Sarcocystis neurona is the primary agent for Equine Protozoal Myeloencephalitis (EPM), important neurological disease characterized by behavior or muscular changes, that impairs animal performance and husbandry. Sarcocystis cruzi is a pathogen related to myositis in cattle. Although related the life cycles of the parasites are distinct. S. neurona has opossums (Didelphis spp.) and S. cruzi, dogs as definitive hosts. However, S. neurona and S. cruzi may undergo cross-reactivity in serological tests, interfering on results of EPM ante-mortem diagnostic tests. In the present study, serology of 189 mares was performed by indirect immunofluorescence antibody test, using antigens of S. neurona and S. cruzi in order to assess the exposure degree of animals to antigens. Analyzing the results, it was observed that most of the animals (84.13%) reacted with at least one protozoal species and the number of animals which showed antibodies against S. cruzi was greater than S. neurona (80.42% and 33.86%, respectively) and a third of seropositive animals reacted to antigens of both species.(AU)

Atividade de nanoformulações de Melaleuca alternifolia e terpinen-4-ol em isolados de Rhodococcus equi / Melaleuca alternifolia activity in nanoformulations and terpinen-4-ol against Rhodococcus equi isolates

Rhodococcus equi é o agente etiológico da rodococose equina, importante doença respiratória de potros. Especialmente na última década, a emergência de cepas resistentes aos antimicrobianos empregados no tratamento da rodococose tem sido relatada. Nesse sentido, há a necessidade de estudos envolvendo terapias alternativas e novas tecnologias, incluindo o uso de plantas medicinais e nanotecnologia. Neste trabalho utilizou-se Melaleuca alternifolia nas seguintes formulações: óleo livre, nanocápsula, nanoemulsão e a combinação de óleo livre com nanocápsula e com nanoemulsão, além do seu composto majoritário, terpinen-4-ol, a fim de verificar a atividade antimicrobiana frente a isolados de R. equi de diferentes origens. Utilizou-se o método de microdiluição em caldo na determinação das concentrações inibitória mínima (CIM) e bactericida mínima (CBM) das diferentes formulações frente aos isolados (n=24). Verificou-se baixo potencial para atividade antibacteriana de M. alternifolia na formulação de óleo livre. Todavia, essa atividade foi potencializada quando se incorporou o óleo essencial às nanoformulações. O composto terpinen-4-ol demonstrou potencial atividade antibacteriana quando incorporado ao óleo essencial e quando utilizado isoladamente. Verificou-se que tanto M. alternifolia quanto terpinen-4-ol testados possuem atividade antimicrobiana contra isolados de R. equi, sugerindo seu emprego em estudos avaliando seu potencial para o tratamento da rodococose.

Rhodococcus equi causes rodococose in horses, characterized by bronchopneumonia in foals. Due to reports of antimicrobial resistance, it is important to develop studies involving alternative therapies and new technologies, including the use of medicinal plants and nanotechnology. In this work, the plant Melaleuca alternifolia in oil free formulations, nanocapsule, nanoemulsion and the combination of free and nanocapsule oil nanoemulsion, besides its major compound, terpinen-4-ol, were used in order to verify antimicrobial activity against isolates of R. equi. The broth microdilution method was employed to determine the minimum inhibitory (MIC) and minimum bactericidal (MBC) concentrations of different formulations against 24 isolates. There was low antibacterial activity of M. alternifolia in oil free formulation; however, it was observed that the activity was enhanced when incorporated as essential oil the nanoformulations. The major compound, terpinen-4-ol, showed bactericidal and bacteriostatic activity when used alone. It is suggested that M. alternifolia, in association with nanocarriers systems, as well as terpinen -4-ol, presents potential for future studies concerning the equine rodococosis therapy.

Soluções de alho (Allium sativum L. ) no controle de nematódeos gastrintestinais em bovinos jovens da raça Holandesa / Garlic (Allium sativum L. ) solutions in control of gastrointestinal nematodes in young Holstein cattle

Para avaliar o efeito da atividade anti-helmíntica do alho suplementado, foram utilizadas 24 bezerras e novilhas da raça Holandesa, naturalmente infectadas. As soluções foram preparadas triturando-se o alho, (50%), mais água ou álcool 92º, (50%), administrando-se oralmente aos animais. Os tratamentos (T) foram constituídos pelo grupo controle negativo (T1); extrato alcoólico de alho a 60g e 120g/100Kg de peso vivo (T2) e (T3); extrato aquoso de alho a 60 e 120g/100kg de peso vivo (T4) e (T5); e o grupo controle positivo com albendazol a 10% (T6). Os tratamentos fitoterápicos foram repetidos a cada 14 dias, caso a infecção fosse superior a 400 ovos por grama de fezes (OPG). A técnica de coprocultura quantitativa e qualitativa foi empregada para avaliar a eficácia anti-helmíntica dos tratamentos. Foram observadas diferenças entre os grupos controle e tratados para OPG e na porcentagem relativa de larvas infectantes e desenvolvimento larval. O uso das soluções de alho demonstrou controle parcial de nematódeos gastrintestinais.

Twenty four Holstein calves and heifers naturally infected were used to evaluate the effect of garlic supply on helminth control. The solutions consisted to triturated garlic, (50%), plus water or alcohol 92º, (50%), orally-administrable on the animals. Treatments (T) consisted of a negative control (T1), garlic at 60 (T2) and 120g on alcoholic extract (T3); 60 (T4) and 120g on aqueous extract/100kg of life weight (T5) and the positive control with albendazol at 10% (T6). The phytotherapic treatments were repeated after 14th day if the infection was superior to 400 eggs per gram of faeces (EPG). The quantitative and qualitative coproculture technique was performed to evaluate the anthelmintic efficacy of the treatments. Differences between treated and control groups were observed in EPG and in relative percentage of infective larvae and the larval development. Partial control was found with the garlic solutions on gastrointestinal nematodes.

Comparative performance of macrocyclic lactones against large strongyles in horses.

Several formulations of macrocyclic lactones (abamectin, ivermectin, moxidectin), including ivermectin combined with pyrantel (tetrahydropyrimidine) and ivermectin combined with praziquantel (pyrazinoisoquinolin derivative), were tested regarding their efficacy to control gastrointestinal nematodes of horses on a stud farm in southern Brazil. In addition, we tested a pharmaceutically produced generic paste containing ivermectin 4%. Similar formulations of avermectins had different efficacies measured by reduction of EPG. Levels of efficacy of the tested drugs varied against Strongylus edentatus, S. equinus and S. vulgaris. The generic paste (ivermectin 4%) was less effective than the conventional drugs.

Infecção rickettsial em Cerro Largo, Rio Grande do Sul / Rickettsial infection in Cerro Largo, State of Rio Grande do Sul, Brazil

O presente estudo teve por objetivo avaliar, por imunofluorescência indireta, infecções ricketsiais em animais e humanos assintomáticos da área rural de Cerro Largo, RS. Dezesseis (51.6%) equinos, seis (22.3%) cães e oito (29.6%) humanos mostraram anticorpos reagentes (título <64) para Ricksettia rickettsii e para Ricksettia parkeri. Os estudos sorológicos indicaram que equinos, cães e humanos entraram em contato com rickettsias do grupo da febre maculosa nesse município. Dois cães mostraram títulos de R. parkeri no mínimo quatro vezes maior que os demais agentes ricketsiais testados e sugerindo que R. parkeri ou um genótipo próximo está circulando na região.

Ocorrência de anticorpos anti-neospora spp. em cavalos de carroça e equinos da raça crioula no estado do Rio Grande do Sul / Occurrence of antibodies anti-neospora spp. in cart horses and crioula breed horses from Rio Grande do Sul state

O objetivo deste estudo foi avaliar a frequência de detecção de anticorpos contra Neospora spp. em cavalos de carroça e em cavalos da raça Crioula. Para tal, 214 amostras de soro foram coletadas e analisadas pela técnica de imunofluorescência indireta, das quais 91 eram de cavalos de carroça e 123 de cavalos da raça Crioula, todas provenientes da região central do Rio Grande do Sul. As frequências de anticorpos detectadas foram: 15,9 por cento (34/214) na população total estudada, 15,4 por cento (14/91) nos cavalos de carroça e 16,3 por cento (20/123) nos cavalos da raça Crioula. Estes resultados sugerem que a infecção por Neospora spp. está presente igualmente nas duas populaç ões. Assim, devido à importância e ao padrão da patogênese da neosporose em equinos, Neospora spp. deve ser incluído no diagnóstico de problemas reprodutivos em éguas e em casos de problemas neurológicos em equinos.

Anticorpos anti-neospora caninum em bovinos de leite do sudoeste do estado do Paraná / Antibodies to neospora caninum in dairy cattle in Southwest of Paraná state

Since November 2007 until May 2009, 1,778 serum samples of cattle from dairy herds of the Southwest of Paraná State, Brazil, were used for search of anti-Neospora caninum antibodies. The frequency of seropositive animals, assessed by IFAT, was 24.2 percent (431/1,178), showing a relatively high occurrence in the studied population. These results show that Neospora caninum is widely distributed in the dairy cattle in the Southwest of Paraná State. The presence of Neospora caninum in a herd is worrisome, since this protozoan is closely related with reproductive disorders and low milk production in cattle.

Anticorpos anti-rickettsias do grupo da febre maculosa em equídeos e caninos no norte do estado do Paraná, Brasil / Anti rickettsia-antibody for spotted fever group in horses and dogs in the north of Paraná stated, Brazil

The Brazilian Spotted Fever (BSF) is a zoonosis that can be fatal if not trteated. As there are few studies of the BSF in the Paraná State, the occurrence of BSF was serologically investigated in dogs and horses by indirect immunofluorescence assay (IFA), in the North of that State, in animals that are regarded as sentinels for BSF. A total of 241 samples of sera of equine, four of asinine, and 29 of dogs were collected in nine farms of three municipalities in the North of Paraná: Arapongas, Douradina, and Umuarama. From fifteen samples of equine serum with positive titres for RIFI, eight (53.3 percent) had titre of 64 against R. rickettsii, two (13.3 percent) 128 against R. rickettsii, and five (33.3 percent) were reactants for R. parkeri and R. rickettsii, with titres ranging from 64 to 2048, and 128 to 1024, respectively. The results showed that domestic animals, sentinels for BSF, are under low exposition to ticks infected with spotted fever group Rickettsia, indicating low risk of human infection by these agents in the studied area.

Cryptosporidium spp. in traction horses in Santa Maria, RS, Brazil / Cryptosporidium spp. em equinos de tração de Santa Maria, RS

Investigou-se a ocorrência de Cryptosporidium spp. em equinos de tração, domiciliados na cidade de Santa Maria, RS. Foram coletadas amostras de fezes diretamente da ampola retal de 52 animais, machos e fêmeas, sem raça definida, na faixa etária do nascimento aos 20 anos de idade. Todos os animais estudados não apresentavam sinal clínico da parasitose. Dentre as amostras analisadas, 38,5 por cento (20/52)foram positivas para oocistos de Cryptosporidium spp. A ocorrência do parasito foi maior em animais jovens (75 por cento; 12/16). Conclui-se que há elevado número de animais assintomáticos eliminando oocistos, que contribuem com a contaminação ambiental e, sobretudo, submetem os carroceiros aos riscos da zoonose.