Colite necrohemorrágica causada por Entamoeba histolytica em um cão / Necro-hemorrhagic colitis caused by Entamoeba histolytica in a dog

Background: Intestinal amebiasis with morphological lesions and clinical manifestations is uncommon in dogs. The disease is caused by the protozoan Entamoeba histolytica, which is commonly observed in its natural hosts, humans and some nonhuman primates. It is occasionally found in the company of animals, usually associated with contact with infected humans. Thus, the objective here is to describe a case of necro-hemorrhagic colitis caused by E. histolytica in a dog infected with the canine distemper virus, in order to characterize the epidemiological and clinicopathological aspects of the disease. Case: An adult, mixed-breed bitch displaying anorexia and ataxia was referred to the veterinary hospital for treatment. Clinical evaluation showed a cachectic animal with 12% dehydration, ocular discharge, and bilateral purulent nasal discharge. A clinical diagnosis of distemper was made, and treatment was instituted. The dog’s signs progressed to walking in circles, aimlessly, with lethargy and blindness. After three days of the onset of neurological signs, the dog developed diarrhea with hematochezia. With no improvement noted, we elected to euthanize the dog. At necropsy, edema was present in subcutaneous tissues, and the lungs had yellow areas in the cranio-ventral portions, which the court was flowing purulent discharge. In the large intestine, segmental distention of the distal portion of the descending colon was observed. The segment was approximately 15 cm in length and consisted of irregular reddish areas. There was also slight thickening of the wall with edematous mucosa containing blood clots, fibrin, and multiple areas of ulceration. Microscopically showed necro-hemorrhagic colitis associated with rounded structures, approximately 15 µm in size, containing abundant eosinophilic cytoplasm that was slightly granular or vacuolated. They also contained nuclei and nucleoli that were central or slightly eccentric […]

Colite necrohemorrágica causada por Entamoeba histolytica em um cão / Necro-hemorrhagic colitis caused by Entamoeba histolytica in a dog

Background: Intestinal amebiasis with morphological lesions and clinical manifestations is uncommon in dogs. The disease is caused by the protozoan Entamoeba histolytica, which is commonly observed in its natural hosts, humans and some nonhuman primates. It is occasionally found in the company of animals, usually associated with contact with infected humans. Thus, the objective here is to describe a case of necro-hemorrhagic colitis caused by E. histolytica in a dog infected with the canine distemper virus, in order to characterize the epidemiological and clinicopathological aspects of the disease. Case: An adult, mixed-breed bitch displaying anorexia and ataxia was referred to the veterinary hospital for treatment. Clinical evaluation showed a cachectic animal with 12% dehydration, ocular discharge, and bilateral purulent nasal discharge. A clinical diagnosis of distemper was made, and treatment was instituted. The dogs signs progressed to walking in circles, aimlessly, with lethargy and blindness. After three days of the onset of neurological signs, the dog developed diarrhea with hematochezia. With no improvement noted, we elected to euthanize the dog. At necropsy, edema was present in subcutaneous tissues, and the lungs had yellow areas in the cranio-ventral portions, which the court was flowing purulent discharge. In the large intestine, segmental distention of the distal portion of the descending colon was observed. The segment was approximately 15 cm in length and consisted of irregular reddish areas. There was also slight thickening of the wall with edematous mucosa containing blood clots, fibrin, and multiple areas of ulceration. Microscopically showed necro-hemorrhagic colitis associated with rounded structures, approximately 15 µm in size, containing abundant eosinophilic cytoplasm that was slightly granular or vacuolated. They also contained nuclei and nucleoli that were central or slightly eccentric […](AU)

Systemic acanthamoebiasis associated with canine distemper in dogs in the semiarid region of Paraíba, Brazil / Acanthamoebíase sistêmica associada a cinomose canina em cães na região semiárida da Paraíba

Infections by free-living amoebae can cause systemic disease in animals and humans. We describe the epidemiological, clinical and pathological aspects of disseminated acanthamoebiasis associated with canine distemper in three dogs of the semiarid region of Paraíba, Northeastern Brazil. Affected dogs developed progressive neurological and respiratory signs that progressed to death within in two to 20 days. Gross lesions were irregular and with yellow-reddish nodules randomly distributed in the lungs, heart, kidneys, spleen, lymph nodes, adrenals, and intestine. One dog had foci of malacia in the parietal cortex and another one in nucleus of brain basis. Histologically, pyogranulomas with areas of necrosis and hemorrhage in all organs affected were observed, associated with myriads of intralesional amoebic trophozoites. All three cases were concomitant canine distemper, that possibly triggered immunosuppression in the dogs. The diagnosis was performed through microscopic findings of infection by free-living amoebae and confirmed Acanthamoeba sp. by immunohistochemistry.(AU)

Infecções por amebas de vida livre podem causar doença sistêmica nos animais e no homem. Descrevem-se os aspectos epidemiológicos, clínicos e patológicos de acanthamoebíase disseminada associada com cinomose em três cães na região semiárida da Paraíba, Nordeste do Brasil. Os cães afetados desenvolveram sinais respiratórios e neurológicos progressivos, que evoluíram para a morte em dois a 20 dias. Na necropsia havia áreas nodulares, irregulares e amarelo-avermelhadas distribuídas aleatoriamente em pulmões, coração, rins, fígado, baço, linfonodos, adrenal e intestino. Em um caso havia foco de malácia no córtex parietal e outro em núcleo da base encefálica. Histologicamente, foram observados piogranulomas com áreas de necrose e hemorragia em todos os órgãos afetados, associados a miríades de amebas intralesionais. Nos três casos havia cinomose concomitante, que possivelmente desencadeou imunossupressão nos cães. O diagnóstico foi realizado através dos achados microscópicos de infecção por amebas de vida livre e confirmado Acanthamoeba sp. pela imuno-histoquímica.(AU)

Differentiation between Entamoeba histolytica and Entamoeba dispar by means of immunoenzymatic assay for antigens detection in children fecal samples / Diferenciação entre Entamoeba histolytica e Entamoeba dispar por meio de ensaio imunoenzimático para pesquisa de antígenos em amostras fecais

The differentiation of the pathogen that cause amebiasis has turned to be relevant since Entamoeba histolytica (pathogenic) has been considered as a distinct species from Entamoeba dispar (non-pathogenic). In the present study E. histolytica antigens were investigated in stool samples from children of São Leopoldo, Rio Grande do Sul, Brazil, by means of a commercially available enzyme-linked immunosorbent assay, ELISA (E. histolytica Test, TechLab Inc., Blacksburg, USA). A total of 262 fecal samples were analyzed by Hoffman, Pons and Janer method, and three samples showed positive result for E. histolytica/E. dispar complex. Of 262 samples, 91 (including those positive on Hoffman, Pons and Janer method) were analyzed by ELISA. The discrepancy of results on coproparasitologic exam and on ELISA was detected as all fecal samples were negative on ELISA, indicating the presence of E. dispar but not of E. Histolytica in those three positive samples on HPJ technique. These data point out the relevance in employing a highly specific technique for performing the identification and differentiation of intestinal amebiasis.

A diferenciação do agente patogênico causador de amebíase obteve grande importância desde que Entamoeba histolytica (patogênica) foi considerada como espécie distinta de Entamoeba dispar (não patogênica). No presente estudo, foi realizada a pesquisa de antígenos de E. histolytica em amostras fecais de crianças residentes na cidade de São Leopoldo, Rio Grande do Sul, Brasil, utilizando-se ensaio imunoenzimático, ELISA (E. histolytica Test, TechLab Inc., Blacksburg, EUA) disponível no comércio. Foram analisadas 262 amostras de fezes pela técnica de Hoffman, Pons e Janer (HPJ), em que três amostras apresentaram positividade para o complexo E. histolytica/E. dispar. Do total de amostras, 91 (incluindo aquelas positivas pela técnica de HPJ) foram analisadas por meio de ELISA. Houve discordância entre os resultados obtidos no exame coproparasitológico e no ELISA, pois todas amostras foram não reagentes no ELISA. Estes dados indicam a presença de E. dispar e ausência de E. histolytica nas três amostras positivas pela técnica de HPJ. Os dados do presente estudo mostram a importância de utilização de técnica mais específica para efetuar identificação e diferenciação da amebíase intestinal.