Bothrops Envenomation in Dogs: Local and Systemic Manifestations:

Background: Snakebite envenoming is a condition that affects humans and domestic animals worldwide. Identification of the snake species involved in the envenomation is infrequent. Bothrops envenomation presents typical clinicopathological features. This report describes epidemiological, clinical, and pathological data of 2 cases of Bothrops envenomation in dogs, including the first case of Bothrops moojeni snake striking a domestic animal in Brazil. Cases: Case 1. A dog was witnessed to have a Bothrops moojeni snakebite on a farm. In the first 24 h, acute lameness, pain, diffuse swelling, focal bleeding at the left forelimb, and increased whole-blood clot­ting time were observed in the envenomed dog. Polyvalent antivenom was administered in addition to fluid therapy, analgesics, corticosteroids, and antibiotics. On the 15th day, the animal presented spontaneous bleeding at the wound site, thrombocytopenia, and increased whole-blood clot­ting time. An additional dose of polyvalent antivenom was administered, and local treatment at the snakebite site was initiated. After 13 days, the dog showed no clinical or laboratory changes and recovered entirely. Case 2. A mongrel dog  was taken for a necropsy to determine the cause of death. Grossly, major findings included swelling in the nasal plane that extended to the neck and dissecting hemorrhage in the subcutaneous tissue and adjacent musculature. Hemorrhages were observed in the heart, parietal pleura, left forelimb, lumbar region, and perirenal tissue. Marked necrosis and disruption of small blood vessels and lymphatics within the deep dermis and subcutaneous tissue were the main microscopic findings close to the snakebite site. Additionally, degeneration and necrosis of muscle fibers and dissecting hemorrhage were observed in the head and neck tissues surrounding the snakebite site. Kidneys showed marked interstitial hemorrhage and acute tubular nephrosis. Discussion: Bothrops envenoming is characterized by local (hemorrhage, dermonecrosis, and myonecrosis) and systemic (coagulative disorders, systemic hemorrhage, and acute kidney injury) changes due to the effect of the main venom components such as phospholipase A2 and metalloproteinases. These changes are hallmarks for the bothropic envenomation, supporting the diagnosis in cases 1 and 2. In case 1, the dog developed a Bothrops moojeni snakebite envenomation, but the immediate treatment with antivenom allowed a favorable outcome. In case 2, gross and microscopic findings supported the presumptive diagnosis of fatal bothropic envenomation. A marked local reaction such as swelling, pain, bleeding, bruising, and tissue necrosis was observed in case 1. In case 2, the most significant local changes were swelling and edema at the head and neck, hemorrhage in the subcutaneous tissue, and adjacent musculature. Systemic effects were observed clinically as spontaneous bleeding, thrombocytopenia, increased whole-blood clot­ting time (Case 1), systemic hemorrhages, and acute tubular nephrosis (Case 2). A proper treatment probably prevented the development of acute renal failure in Case 1. Herein, we show the first case of accidental snakebite envenomation by B. moojeni in a dog in Brazil. Information is scarce on the identification of venomous snake species striking domestic animals. Fast detection of well-determined clinical and pathological findings of Bothrops envenomation is essential for a correct diagnosis, therapeutics, and a good prognosis, even in cases with an unknown history.   Keywords: Bothrops moojeni, venomous, coagulative disorders, canine, snake, snakebite

Cerebral Vascular Hamartoma In a Campeiro Bulldog

Background: Vascular hamartomas (VH) are rare or simply underdiagnosed injuries in veterinary medicine and represent a non-neoplastic developmental anomaly disorganization and proliferation of endothelial tissue. VH occur in any region of the body, however in the brain present clinical relevance related with the potential for spontaneous bleeding, adjacent tissue compression and convulsive activity. The aim of these report is to describe clinical, pathological and immunohistochemical features of a case of cerebrovascular hamartoma and highlight the diagnosis of these rare brain disorder in dogs.Case: A 10-year-old male dog, a Campeiro Bulldog breed presented convulsions episodes and died before an elective surgical procedure for eyelid nodule removal. Three red nodules were observed in the brain, one between the parietal lobe and the left occipital lobe (in the medium suprasylviam sulcus), the other in the caudal region of the corpus callosum and the third one in the cerebellar cortex. Central nervous system, eyelids and most organs and tissues samples were collected, fixed in 10% formaldehyde and processed for histopathological analysis. Histologically, in the eyelid was detected a sebaceous adenoma. The nervous system samples revealed well-differentiated different sizes vascular structures with thin-walled and blood-filled, promoting compression of the brain. Normal neuropile was detected between the vascular structures substantiating cerebral vascular hamartoma diagnosis in the dog. Immunohistochemical assay was conducted with CD31 (monoclonal mouse antibody anti-CD31, Clone JC70A, Dako Corp.) and Von Willebrand factor (monoclonal mouse antibody anti-Von Willebrand factor, Clone F8/86, Dako Corp.) using the biotin–peroxidase–streptavidin method (PolyDetector Plus DAB–HRP, Bio SB) on CNS sections to confirm the vascular origin of the lining cells in the mass. Discussion: Hamartomas are rarely reported in domestic animals and mostly are of vascular origin. VH in nervous tissues can trigger clinical signs related to hemorrhage, brain space occupation, compression and obstructive secondary hydrocephalus. In general, cerebral VH have a slow progression and usually affected animals are asymptomatic. On the other hand, cerebral vascular hamartomas may also cause clinical signs in very young animals about 15 to 16 months old. In humans, clinical presentation of VH may be related with acquired lesions such as trauma, ionizing radiation, and other central nervous system injuries. In the present case, the dog presented convulsion episode only at 10 years old during pre-chirurgical procedures. The morphological features of the vascular hamartoma we observed in the Campeiro bulldog is classified as capillary teleangiectasia composed by well differentiated capillaries lined with well differentiated endothelial cells interspaced by normal neuronal tissue. Histopathological and immunohistochemical assay are extremely important to differentiate hamartoma from other tumors, since they may be macroscopically similar. The immunolabeling of endotelial cells by anti-CD31 and anti-Von Willebrand factor antibodies in the cerebral VH, highlight the vascular origin of the masses detected. However, it is also important to perform systematic gross examination of the brain in detail to detect even the smallest injuries in asymptomatic animals avoiding underdiagnoses of cerebral VH

Immunopathological findings in a cat with auricular chondritis

At clinical examination, a 5-year-old male domestic short-haired cat exhibited painful swelling and erythema of the pinnae of both ears. Microscopically, the lesions on both pinnae were composed of diffuse granulomatous chondritis with degeneration and necrosis of the pinnal cartilage. Numerous mast cells were also observed within and surrounding the inflammatory lesion. Immunohistochemistry showed a mixed inflammatory infiltrate characterised by the predominance of macrophages (CD68+, MAC 387+ and Lysozyme+), T lymphocytes (CD3+), some B lymphocytes (CD79α+) and neutrophils. Immunopathological characterisation of the lesion showed a granulomatous inflammation profile and suggests that the morphological changes and immunopathogenesis of auricular chondritis in cats presents a similarity with relapsing polychondritis in humans

Outbreak of Monensin Sodium Poisoning in Horses Associated with Consumption of Mineral Supplement Based on Sugarcane Molasses

Background: Sodium monensin is a molecule of the group of ionophores antibiotics (IAs) of the polyether carboxylic type produced from the fermentation of Streptomyces cinnamonensis. Cases of IA poisoning in animals usually occur accidentally. Fatal poisoning in horses, a non-target species and with particular sensitivity usually occurs by the consumption of these products from the toxic dose of 2-3 mg/kg. This report aims to describe the epidemiological and clinical-pathological aspects of an outbreak of ionophore antibiotic poisoning in horses due to the consumption of mineral supplementation indicated for ruminants based on sugarcane molasses.Case: Two horses were necropsied. During necropsy, fragments of various organs were collected and fixed in 10% buffered formalin, routinely processed for histology and stained with hematoxylin and eosin. The information obtained from the animal trainer was that 19 horses received approximately 25 kg of low moisture mixture based on sugarcane molasses, enriched with macro and micro minerals, vitamins and additives containing 1000 mg of monensin/kg in the trough. One day after receiving the product, five horses began to develop ataxia, reluctance to move, difficulty of accompanying the herd and arising. Out of the five, three died after three days of evolution, one after six days (equine 1) and another after 15 days (equine 2) [morbidity 26.31%]. At necropsy, diffuse pallor was observed in the gluteus medius, quadriceps femoris, semimembranosus, biceps brachii and deep pectoral muscles. Microscopically the muscle fibers were tumefied with hypereosinophilic sarcoplasm of homogeneous appearance and with loss of striations, pynotic or absent nuclei (necrosis). Multifocal areas of fibers with sarcoplasmic fragmentation were observed, with clusters of irregular eosinophilic debris, flake (floct necrosis) or granule (granular necrosis) aspects and focal muscle fibers with granular to crystalline basophilic material (mineralization) and marked multifocal infiltrate, predominantly of macrophages, plasma cells and eosinophils with occasional multinucleated giant cells. In the heart there was focally a extensive area of necrosis and a discrete eosinophil infiltrate.Discussion: The diagnosis of ionophore antibiotic intoxication in horses was established by epidemiological and clinical-pathological aspects. In the horses affected in this outbreak, the intoxication was due to the ingestion of sugarcane molasses containing proportions of monensin, which is not indicated for equines, becoming an unusual source for this animal species. The clinical signs reported in the intoxication under study are mostly locomotors and are directly linked to poor distribution of sodium, potassium and calcium ions in muscle cells, leading to ionic disorders that modify the muscle neurotransmission by deregulating contraction and altering movement. Usually, death of horses poisoned with IAs is related to heart failure due to degenerative cardiomyopathy. However, due to the subtlety of the histological lesions in the heart, we believe that the cause of death may also be related to a possible respiratory failure owing to a degenerative myopathy of the diaphragmatic muscle. The anatomopathological changes found in the skeletal muscles of equine intoxicated with molasses are similar to those described in this species by other authors. Compounds based on sugarcane molasses formulated for cattle containing monensin should be considered as a potential source of poisoning for horses and as a cause of degenerative myopathy, which may be an alert for caring about the handling and feeding of these animals.

Pathological investigation of infectious diseases in free- ranging black-tufted marmosets (Callitrix penicillata) and implications for public health and conservation in Brazil

Tese (doutorado) — Universidade de Brasília, Faculdade de Agronomia e Medicina Veterinária, 2021.Várias infecções emergentes que se tornaram epidêmicas em humanos tiveram origem em não humanos primatas (PNHs). Esses eventos de transmissão de doenças podem ser causados por alterações feitas pelo homem para habitats animais e são essenciais para o ponto de vista de Saúde Única. Agentes etiológicos de doenças infecciosas fatais doenças podem ser diagnosticadas testes laboratoriais de tecidos, uma vez que tal necropsia é fundamental para melhorar reconhecimento de doenças infecciosas emergentes e reemergentes. A maioria dos estudos de doenças infecciosas doenças em PNHs são baseadas em levantamentos sorológicos ou moleculares, há dados limitados sobre doenças infecciosas e doenças como causa de óbitos em PNHs no Brasil. Doença infecciosa fatais natural como causa de óbito foram investigados no Laboratório de Patologia Veterinária da Universidade de Brasília como integrante do Programa Nacional de Vigilância das Epizootias de Febre Amarela na PNH do Brasil Ministério da Saúde. Esta investigação levou à identificação de outras doenças infecciosas fatais em NHPs; aqui nós descrevemos, a partir de 1.042 casos recuperados, achados histopatológicos, imunohistoquímicos, diagnóstico molecular e investigação epidemiológica da infecção fatal por Leptospira interrogans em um sagui-de-tufo-preto (Callithrix penicilatta) urbanizado, de vida livre, no Brasil. Leptospirose fatal em PNHs é rara, este é o primeiro relato de leptospirose fatal em um PNH de vida livre descrevendo achados essenciais para facilitar o diagnóstico post- mortem de leptospirose e compreensão da doença no PNH. A aplicação da perspectiva Saúde Única leva em consideração o possível papel dos NHPs na epidemiologia e dinâmica de transmissão de humanos e animais leptospirose e potencial de transmissaão de patógenos na interface humano-PNH em áreas antropizadas. Os PNH são importantes sentinelas de algumas doenças zoonóticas no Brasil, e esses animais também podem indicam riscos de leptospirose no meio ambiente. Outro aspecto da perspectiva de Uma Saúde é zoonoses reversas, onde doenças humanas podem se espalhar para populações vulneráveis de vida selvagem. Isto é uma preocupação para as populações de saguis. Aqui, descrevemos o clínico-patológico achados clínico-patológicos, imunohistoquímicos, moleculares e ultraestruturais de infecção fatal pelo vírus herpes simplex tipo 1 (HSV-1) em 13 saguis-de- tufo-preto de vida livre áreas urbanizadas, no Brasil. Meningoencefalite necrotizante, glossite ulcerativa, e hepatite necrotizante com inclusões virais intranucleares foram caracteristicas da doença. Antígenos de HSV-1 foram localizados por imunohistoquímica e partículas virais por transmissão de elétrons microscopia dentro das células neurais, epitélio da língua e hepatócitos. O teste de PCR confirmou o HSV-1 em todos os casos. Embora quase todos os relatos anteriores de infecção por HSV-1 em saguis sejam de animais de cativeiro, nossos resultados destacam o risco de transmissão de doenças infecciosas interespécies noainterface humano- animal em ambientes antropizados e enfatiza a importância de uma abordagem de Saúde Única para vigilância de doenças infecciosas nesses locais.Several emerging infections that became epidemic in humans have originated in non-human primates (NHPs). These disease transmission events can be driven by man-made alterations to animal habitats and are essential for a One Health viewpoint. Etiologic agents of fatal infectious diseases can be diagnosed laboratory testing of tissues, as such necropsy is key for improving recognition of emerging and re-emerging infectious diseases. Most of the studies of infectious diseases in NHPs are based on serological or molecular assays, there are limited data on infectious diseases as the cause of deaths in NHPs in Brazil. Natural fatal infectious diseases as a cause of death were investigated in the Veterinary Pathology Laboratory at the University of Brasilia as part of the National Surveillance Program of Yellow Fever Epizootics in NHP of the Brazilian Ministry of Health. This investigation lead to the identification of other fatal infectious diseases in NHPs; herein we describe, from 1,042 cases retrieved, histopathological, immunohistochemical, molecular diagnosis, and epidemiological investigation of fatal Leptospira interrogans infection in an urbanized, free- ranging, black-tufted marmoset (Callithrix penicilatta) in Brazil. Fatal leptospirosis in NHPs is rare, this is the first report of fatal leptospirosis in a free-ranging NHP describing findings essential to facilitate the postmortem diagnosis of leptospirosis and understanding the disease in NHP. Applying the One Health perspective brings into consideration the possible role of NHPs in the epidemiology and transmission dynamics of human and animal leptospirosis, and potential of pathogen spillover at the human-NHP interface in anthropized areas. NHP are important sentinels for some zoonotic diseases in Brazil, and these animals could also indicate leptospirosis risks in the environment. Another aspect on the One Health perspective is reverse zoonoses, where human diseases can be spread to vulnerable wildlife populations. This is a concern for marmoset populations. Herein we describe the clinicopathological clinicopathological, immunohistochemical, molecular, and ultrastructural findings of fatal human herpes simplex virus type 1 (HSV-1) infection in 13 urbanized, free-ranging, black- tufted marmosets (Callithrix penicilatta) in Brazil. Necrotizing meningoencephalitis, ulcerative glossitis, and necrotizing hepatitis with intranuclear viral inclusions were hallmarks of the disease. We localized HSV-1 antigens by immunohistochemistry and viral particles by transmission electron microscopy within neural cells, tongue epithelium, and hepatocytes. PCR testing confirmed HSV1 in all cases. While nearly all prior reports of HSV-1 infection in marmosets are from captive animals, our findings highlight the risk of interspecies infectious disease transmission at the human-animal interface in anthropized environments and emphasize the importance of a One Health approach to infectious disease surveillance in these settings

Correlation of non-neoplastic mammary lesions with type and histological grade of dogs with mammary neoplasm

Few studies analyzing non-neoplastic lesions (NNL) in mammary gland of female dogs, as well as the relation between the presence of these alterations and the simultaneous occurrence of mammary neoplasias, either in the mammary tissue adjacent of mammary neoplasm or in the other breasts of the mammary chain with tumor. The objective of this study was to determine the occurrence of non-neoplastic lesions in the mammary tissue adjacent to tumors in breasts with no palpable nodules located in the mammary chains of female dogs with neoplasms and to correlate with histological type and grade of carcinoma. For this, a histological analysis of 314 breast samples with or without a palpable nodule of 68 bitches submitted to mastectomy was performed. The neoplastic and non neoplastic alterations located adjacent to the tumors and also in the breasts without palpable nodules in the mammary chain were identified. Their occurrence was associated with malignant neoplasms and benign by a contingency analysis (Fischer's exact test). The minimum age of bitches in this study (3 years) coincides with the occurrence of the first or second estrous cycle. In breasts with no palpable nodules associated with breast neoplasms there is an occurrence of NNL and neoplastic lesions, demonstrating the risk of developing a new mammary neoplasia in other glands of dogs diagnosed with breast carcinoma. This data reinforces the recommendation to perform total mastectomy, even in female dogs with only one node in the chain. NNL of the gland adjacent to neoplasias and in the other breasts without nodules were more frequently associated with malignant neoplasias when compared with benign neoplasias. Mammary glands without nodules in mammary chains with more than one type of malignant neoplasm had more NNL than those with only one type of neoplasia. ALH, which is considered the precursor of invasive breast carcinomas in bitches, occurred more frequently associated with carcinomas than other types of hyperplasia.Dissertação (Mestrado)São escassos estudos de lesões não neoplásicas (LNN) em cães, assim como a relação entre a presença destas alterações e a ocorrência simultânea de neoplasias mamárias,seja na mama adjacente ou nas demais mamas da cadeia mamária onde ocorreu o tumor. O objetivo desse estudo foi determinara ocorrência de lesões não neoplásicas no parênquima mamário adjacente a tumores e em mamas sem nódulos palpáveis localizadas em cadeias mamárias de cadelas com neoplasias e correlacionar com tipo e grau histológico de carcinoma.Para tanto, foi feita análise histopatológica de 314 amostras de mama com ou sem nódulo palpável de 68 cadelas submetidas à mastectomia. As alterações neoplásicas e não neoplásicas localizadas adjacentes aos tumores e também nas mamas sem nódulos palpáveis na cadeia mamária foram identificadas esua ocorrência foi associada com neoplasias malignas e benignas por análise de contingência(Teste exato de Fischer). A idade mínima das cadelas nesse estudo (3 anos) coincide com a ocorrência do primeiro ou segundo ciclo estral. Em mamas sem nódulos palpáveis associadas a neoplasias na cadeia mamária há ocorrência de LNN e neoplásicas, demonstrando o risco de desenvolvimento de uma nova neoplasia mamária em outras glândulas de cadelas diagnosticadas com carcinoma mamário. Este dado reforça a recomendação de se realizar mastectomia total, mesmo em cadelas que apresentem apenas um nódulo na cadeia. As LNN da glândula adjacente a neoplasias e nas demais mamas sem nódulos estavam mais frequentemente associadas a neoplasias malignas quando comparadas com as neoplasias benignas. As mamas sem nódulos nas cadeias mamárias com mais de um tipo de neoplasia maligna tiveram mais LNN do que aquelas com apenas um tipo de neoplasia. HLA, que é considerada precursora de carcinomas invasivos de mama em cadelas, ocorreu com maior freqüência associada aos carcinomas do que os demais tipos de hiperplasia

Quimiodectoma maligno em um cão Weimaraner: Relato de caso

O presente relato de caso tem como finalidade descrever uma ocorrência de quimiodectoma de caráter maligno em um cão de raça weimaraner. Quimiodectomas são neoplasias formadas a partir de quimiorreceptores presentes na base do coração envolvendo o corpo aórtico e carótido, pode ser benigno (mais comum) ou maligno. Estes tumores são pouco frequentes na clínica de pequenos animais e, quando ocorrem, geralmente estão associados a cães idosos e de raças braquiocefálicas (boxer, bulldog, dentre outros). O diagnóstico clínico é dificultoso, pois a maioria dos animais acometidos são assintomáticos, e, quando presentes, os sinais clínicos são inespecíficos, sendo, portanto, diagnosticados através dos exames radiográficos de rotina ou como achados nos exames post-mortem. No presente caso, o animal foi a atendimento clínico por outro motivo (nódulos subcutâneos), tendo sido investigado o quimiodectoma após ser percebido aumento de frequência respiratória e tamponamento de sons pulmonares em algumas regiões torácicas. O diagnóstico final foi possível após radiografia torácica e histopatologia do tecido tumoral através de técnica “tru-cut” com auxílio de ultrasonografia com ferramenta Doppler. Além de se referir à ocorrência de quimiodectoma em uma raça não predisposta, a importância do presente trabalho também se dá à abordagem do proprietário frente a uma patologia crônica maligna sem possibilidade de correção

Bothrops Envenomation in Dogs: Local and Systemic Manifestations:

Background: Snakebite envenoming is a condition that affects humans and domestic animals worldwide. Identification of the snake species involved in the envenomation is infrequent. Bothrops envenomation presents typical clinicopathological features. This report describes epidemiological, clinical, and pathological data of 2 cases of Bothrops envenomation in dogs, including the first case of Bothrops moojeni snake striking a domestic animal in Brazil. Cases: Case 1. A dog was witnessed to have a Bothrops moojeni snakebite on a farm. In the first 24 h, acute lameness, pain, diffuse swelling, focal bleeding at the left forelimb, and increased whole-blood clot­ting time were observed in the envenomed dog. Polyvalent antivenom was administered in addition to fluid therapy, analgesics, corticosteroids, and antibiotics. On the 15th day, the animal presented spontaneous bleeding at the wound site, thrombocytopenia, and increased whole-blood clot­ting time. An additional dose of polyvalent antivenom was administered, and local treatment at the snakebite site was initiated. After 13 days, the dog showed no clinical or laboratory changes and recovered entirely. Case 2. A mongrel dog  was taken for a necropsy to determine the cause of death. Grossly, major findings included swelling in the nasal plane that extended to the neck and dissecting hemorrhage in the subcutaneous tissue and adjacent musculature. Hemorrhages were observed in the heart, parietal pleura, left forelimb, lumbar region, and perirenal tissue. Marked necrosis and disruption of small blood vessels and lymphatics within the deep dermis and subcutaneous tissue were the main microscopic findings close to the snakebite site. Additionally, degeneration and necrosis of muscle fibers and dissecting hemorrhage were observed in the head and neck tissues surrounding the snakebite site. Kidneys showed marked interstitial hemorrhage and acute tubular nephrosis. Discussion: Bothrops envenoming is characterized by local (hemorrhage, dermonecrosis, and myonecrosis) and systemic (coagulative disorders, systemic hemorrhage, and acute kidney injury) changes due to the effect of the main venom components such as phospholipase A2 and metalloproteinases. These changes are hallmarks for the bothropic envenomation, supporting the diagnosis in cases 1 and 2. In case 1, the dog developed a Bothrops moojeni snakebite envenomation, but the immediate treatment with antivenom allowed a favorable outcome. In case 2, gross and microscopic findings supported the presumptive diagnosis of fatal bothropic envenomation. A marked local reaction such as swelling, pain, bleeding, bruising, and tissue necrosis was observed in case 1. In case 2, the most significant local changes were swelling and edema at the head and neck, hemorrhage in the subcutaneous tissue, and adjacent musculature. Systemic effects were observed clinically as spontaneous bleeding, thrombocytopenia, increased whole-blood clot­ting time (Case 1), systemic hemorrhages, and acute tubular nephrosis (Case 2). A proper treatment probably prevented the development of acute renal failure in Case 1. Herein, we show the first case of accidental snakebite envenomation by B. moojeni in a dog in Brazil. Information is scarce on the identification of venomous snake species striking domestic animals. Fast detection of well-determined clinical and pathological findings of Bothrops envenomation is essential for a correct diagnosis, therapeutics, and a good prognosis, even in cases with an unknown history.   Keywords: Bothrops moojeni, venomous, coagulative disorders, canine, snake, snakebite

Sensibilidade do teste parasitológico em imprints de baço, medula óssea e linfonodo para o diagnóstico da leishmaniose de acordo com o número de avaliadores

A Leishmaniose Visceral é considerada pela Organização Mundial de Saúde uma das seis endemias prioritárias no mundo, sendo que os cães atuam como reservatórios naturais do parasito. O diagnóstico da enfermidade nos cães é discutido e o propósito do presente trabalho foi de verificar o método parasitológico como meio de diagnóstico da Leishmaniose Visceral Canina utilizando amostras de baço, medula óssea e linfonodo, além de correlacionar com a sintomatologia clínica dos animais e analisar a sensibilidade do diagnóstico parasitológico realizado por um e dois observadores. Foram utilizados 59 cães obtidos pelo Centro de Controle de Zoonoses de Uberlândia - MG. Os animais foram examinados clinicamente antes da eutanásia e classificados em assintomáticos (grupo 1) (n=6), oligossintomáticos (grupo 2) (n=34) e sintomáticos (grupo 3) (n=19). Trinta e três (55,93%) animais foram positivos e destes 20 (60,60%) pertenciam ao grupo 2, 11 (33,33%) ao grupo 3 e 2 (6,06%) ao grupo 1. Em relação aos locais de coleta analisados obteve-se 73 (41,24%) amostras positivas, sendo 28 (38,35%) de medula óssea, 25 (34,24%) de baço e 20 (27,39%) de linfonodo. Quando a leitura foi realizada por um observador obteve-se 13 (22,03%) animais positivos, e com dois observadores este número foi de 33 (55,93%), sendo este aumento na sensibilidade significativo estatisticamente. Não houve diferença estatística entre o número de animais distribuídos entre os grupos com sintomatologia clínica e tampouco quanto ao local puncionado. Recomenda-se a leitura realizada por dois observadores para aumento na sensibilidade do teste parasitológic