RESUMO
BACKGROUND: Hundreds of millions of domestic carnivores worldwide have diverse positive affiliations with humans, but can provoke serious socio-ecological impacts when free-roaming. Unconfined dogs (Canis familiaris) and cats (Felis catus) interact with wildlife as predators, competitors, and disease-transmitters; their access to wildlife depends on husbandry, perceptions, attitudes, and behaviors of pet owners and non-owners. METHODS: To better understand husbandry and perceptions of impacts by unconfined, domestic carnivores, we administered questionnaires (n = 244) to pet owners and non-owners living in one of the last wilderness areas of the world, the Cape Horn Biosphere Reserve, located in southern Chile. We used descriptive statistics to provide demographic pet and husbandry information, quantify free-roaming dogs and cats, map their sightings in nature, and report experiences and perceptions of the impact of free-roaming dogs and cats on wildlife. We corroborated our results with an analysis of prey remains in dog feces (n = 53). With generalized linear models, we examined which factors (i.e., food provisioning, reproductive state, rural/village households, sex, and size) predicted that owned dogs and cats bring wildlife prey home. RESULTS: Thirty-one percent of village dogs (n = 121) and 60% of dogs in rural areas (n = 47) roamed freely day and/or night. Free-roaming dog packs were frequently observed (64% of participants) in the wild, including a feral dog population on Navarino Island. Dogs (31 of 168) brought home invasive muskrats (Ondatra zibethicus) and avian prey, and over half of all cats (27 of 51) brought home mainly avian prey. Birds were also the most harassed wildlife category, affected by one third of all dogs and cats. Nevertheless, dog-wildlife conflicts were hardly recognized (<9% of observed conflicts and suspected problems), and only 34% of the participants thought that cats might impact birds. Diet analysis revealed that dogs consumed livestock (64% of 59 prey occurrences), beavers (Castor canadensis, 14%), and birds (10%). The probability that dogs brought prey to owners' homes was higher in rural locations and with larger dogs. There was also evidence that cats from rural households and with an inadequate food supply brought more prey home than village cats. DISCUSSION: Although muskrat, beavers, and birds were brought home, harassed, or found in dog feces, free-roaming dogs and, to a lesser extent, cats are perceived predominantly in an anthropogenic context (i.e., as pets) and not as carnivores interacting with wildlife. Therefore, technical and legal measures should be applied to encourage neutering, increase confinement, particularly in rural areas, and stimulate social change via environmental education that draws attention to the possibility and consequences of unconfined pet interaction with wildlife in the southernmost protected forest ecoregion of the globe.
RESUMO
Dogs are as considered important reservoirs of trypanosomiasis and play a vital role in maintaining the interaction between the domestic and wild cycles of this disease. This paper reports the clinical and pathological findings of a case of Chagas disease myocarditis in a dog from an urban area in Brazil. During clinical examination, the animal showed apathy, weakness and pale ocular mucous and died shortly after. Necropsy revealed ascites, hydrothorax and hydropericardium. The heart was remarkably globoid with scattered multifocal pale in the epicardium and ventricular miocardium and dilated chambers. Histological analysis revealed non-suppurative myocarditis and cardiomyocyte necrosis. The sarcoplasms of cardiomyocytes were frequently infiltrated by T. cruzi pseudocysts filled with amastigotes. The myocardium immunostained positive for anti-T. cruzi antibody. The presence of Chagas disease in a dog from an urban area increases the risk of disease transmission to man, which renders this diagnosis a matter of significant public health concern.(AU)
Os cães são considerados importantes reservatórios de tripanosomose e têm um relevante papel na manutenção e interação entre o ciclo doméstico e silvestre desta doença. Neste trabalho é descrito as alterações clínicas e anatomopatológicas de miocardite chagásica em um cão, domiciliado em área urbana, no Brasil. Durante o exame clínico o animal apresentava apatia, debilidade e mucosas oculares pálidas, com rápida evolução para o óbito. Na necropsia foram observados ascite, hidrotórax e hidropericárdio. O coração estava globoso com áreas multifocais pálidas no epicárdio e miocárdio ventricular e ao corte observou-se dilatação das câmaras átrio-ventriculares. Histologicamente, no coração havia miocardite não supurativa e necrose de cardiomiócitos. Frequentemente, infiltrando o sarcoplasma de cardiomiócitos, haviam pseudocistos de T. cruzi contendo múltiplas amastigotas. No exame de imuno-histoquímica, do miocárdio, houve imunomarcação positiva para o anticorpo anti-T. cruzi. A ocorrência da doença de Chagas em um canino domiciliado em área urbanizada eleva os riscos de transmissão da doença para o homem, o que consequentemente torna este diagnóstico uma nota de importância em saúde pública e de diferencial para outras patologias caninas.(AU)
Assuntos
Animais , Cães , Doença de Chagas/veterinária , Trypanosoma cruzi/patogenicidade , Cardiomiopatia Chagásica/veterinária , Cardiomiopatia Chagásica/fisiopatologia , Imuno-HistoquímicaRESUMO
Dogs are as considered important reservoirs of trypanosomiasis and play a vital role in maintaining the interaction between the domestic and wild cycles of this disease. This paper reports the clinical and pathological findings of a case of Chagas disease myocarditis in a dog from an urban area in Brazil. During clinical examination, the animal showed apathy, weakness and pale ocular mucous and died shortly after. Necropsy revealed ascites, hydrothorax and hydropericardium. The heart was remarkably globoid with scattered multifocal pale in the epicardium and ventricular miocardium and dilated chambers. Histological analysis revealed non-suppurative myocarditis and cardiomyocyte necrosis. The sarcoplasms of cardiomyocytes were frequently infiltrated by T. cruzi pseudocysts filled with amastigotes. The myocardium immunostained positive for anti-T. cruzi antibody. The presence of Chagas disease in a dog from an urban area increases the risk of disease transmission to man, which renders this diagnosis a matter of significant public health concern.
Os cães são considerados importantes reservatórios de tripanosomose e têm um relevante papel na manutenção e interação entre o ciclo doméstico e silvestre desta doença. Neste trabalho é descrito as alterações clÃnicas e anatomopatológicas de miocardite chagásica em um cão, domiciliado em área urbana, no Brasil. Durante o exame clÃnico o animal apresentava apatia, debilidade e mucosas oculares pálidas, com rápida evolução para o óbito. Na necropsia foram observados ascite, hidrotórax e hidropericárdio. O coração estava globoso com áreas multifocais pálidas no epicárdio e miocárdio ventricular e ao corte observou-se dilatação das câmaras átrio-ventriculares. Histologicamente, no coração havia miocardite não supurativa e necrose de cardiomiócitos. Frequentemente, infiltrando o sarcoplasma de cardiomiócitos, haviam pseudocistos de T. cruzi contendo múltiplas amastigotas. No exame de imuno-histoquÃmica, do miocárdio, houve imunomarcação positiva para o anticorpo anti-T. cruzi. A ocorrência da doença de Chagas em um canino domiciliado em área urbanizada eleva os riscos de transmissão da doença para o homem, o que consequentemente torna este diagnóstico uma nota de importância em saúde pública e de diferencial para outras patologias caninas.
RESUMO
Dogs are as considered important reservoirs of trypanosomiasis and play a vital role in maintaining the interaction between the domestic and wild cycles of this disease. This paper reports the clinical and pathological findings of a case of Chagas disease myocarditis in a dog from an urban area in Brazil. During clinical examination, the animal showed apathy, weakness and pale ocular mucous and died shortly after. Necropsy revealed ascites, hydrothorax and hydropericardium. The heart was remarkably globoid with scattered multifocal pale in the epicardium and ventricular miocardium and dilated chambers. Histological analysis revealed non-suppurative myocarditis and cardiomyocyte necrosis. The sarcoplasms of cardiomyocytes were frequently infiltrated by T. cruzi pseudocysts filled with amastigotes. The myocardium immunostained positive for anti-T. cruzi antibody. The presence of Chagas disease in a dog from an urban area increases the risk of disease transmission to man, which renders this diagnosis a matter of significant public health concern.
Os cães são considerados importantes reservatórios de tripanosomose e têm um relevante papel na manutenção e interação entre o ciclo doméstico e silvestre desta doença. Neste trabalho é descrito as alterações clÃnicas e anatomopatológicas de miocardite chagásica em um cão, domiciliado em área urbana, no Brasil. Durante o exame clÃnico o animal apresentava apatia, debilidade e mucosas oculares pálidas, com rápida evolução para o óbito. Na necropsia foram observados ascite, hidrotórax e hidropericárdio. O coração estava globoso com áreas multifocais pálidas no epicárdio e miocárdio ventricular e ao corte observou-se dilatação das câmaras átrio-ventriculares. Histologicamente, no coração havia miocardite não supurativa e necrose de cardiomiócitos. Frequentemente, infiltrando o sarcoplasma de cardiomiócitos, haviam pseudocistos de T. cruzi contendo múltiplas amastigotas. No exame de imuno-histoquÃmica, do miocárdio, houve imunomarcação positiva para o anticorpo anti-T. cruzi. A ocorrência da doença de Chagas em um canino domiciliado em área urbanizada eleva os riscos de transmissão da doença para o homem, o que consequentemente torna este diagnóstico uma nota de importância em saúde pública e de diferencial para outras patologias caninas.
RESUMO
Dogs are as considered important reservoirs of trypanosomiasis and play a vital role in maintaining the interaction between the domestic and wild cycles of this disease. This paper reports the clinical and pathological findings of a case of Chagas disease myocarditis in a dog from an urban area in Brazil. During clinical examination, the animal showed apathy, weakness and pale ocular mucous and died shortly after. Necropsy revealed ascites, hydrothorax and hydropericardium. The heart was remarkably globoid with scattered multifocal pale in the epicardium and ventricular miocardium and dilated chambers. Histological analysis revealed non-suppurative myocarditis and cardiomyocyte necrosis. The sarcoplasms of cardiomyocytes were frequently infiltrated by T. cruzi pseudocysts filled with amastigotes. The myocardium immunostained positive for anti-T. cruzi antibody. The presence of Chagas disease in a dog from an urban area increases the risk of disease transmission to man, which renders this diagnosis a matter of significant public health concern.
Os cães são considerados importantes reservatórios de tripanosomose e têm um relevante papel na manutenção e interação entre o ciclo doméstico e silvestre desta doença. Neste trabalho é descrito as alterações clínicas e anatomopatológicas de miocardite chagásica em um cão, domiciliado em área urbana, no Brasil. Durante o exame clínico o animal apresentava apatia, debilidade e mucosas oculares pálidas, com rápida evolução para o óbito. Na necropsia foram observados ascite, hidrotórax e hidropericárdio. O coração estava globoso com áreas multifocais pálidas no epicárdio e miocárdio ventricular e ao corte observou-se dilatação das câmaras átrio-ventriculares. Histologicamente, no coração havia miocardite não supurativa e necrose de cardiomiócitos. Frequentemente, infiltrando o sarcoplasma de cardiomiócitos, haviam pseudocistos de T. cruzi contendo múltiplas amastigotas. No exame de imuno-histoquímica, do miocárdio, houve imunomarcação positiva para o anticorpo anti-T. cruzi. A ocorrência da doença de Chagas em um canino domiciliado em área urbanizada eleva os riscos de transmissão da doença para o homem, o que consequentemente torna este diagnóstico uma nota de importância em saúde pública e de diferencial para outras patologias caninas.
RESUMO
Stray dogs are considered as sentinels in the epidemiology of Toxoplasma gondii because they are carnivores and eat a variety of foods, including garbage. In the present study, tissues and sera of 249 stray dogs (Canis familiaris) from Grenada, West Indies were examined for T. gondii infection. Sera were examined for antibodies to T. gondii by the modified agglutination test (MAT); 89 (35.7%) of 249 were seropositive with titers of 25 in seven dogs, 50 in 22 dogs, 100 in 22 dogs, 200 or higher in 38 dogs. Hearts of 76 seropositive dogs were bioassayed in mice. Viable T. gondii was isolated from 12 dogs; these isolates were designated TgDogGr1 to TgDogGr12. These isolates were further propagated in cell culture and DNA isolated from cell culture derived tachyzoites of 12 isolates was genotyped using 10 PCR-restriction fragment length polymorphism markers (SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico). The results revealed six genotypes, including ToxoDB PCR-RFLP #1, #2, #3, #7, #13 and #224, with 1, 6, 1, 2, 1 and 1 isolates, respectively. The result supports previous findings that T. gondii population genetics is highly diverse in Grenada.