RESUMO
BACKGROUND: In an era of unprecedented socio-ecological changes, managing wildlife health demands high-quality data collection and the engagement of local communities. Blastocerus dichotomus, the largest South American deer, is Vulnerable to extinction mainly due to habitat loss. Diseases have been recognised as a potential threat, and winter mortality has been historically described in marsh deer populations from Argentina. Field difficulties have, however, prevented in-depth studies of their health status. RESULTS: Between May 2014 and April 2017, we investigated marsh deer morbidity and mortality in the two largest populations in Argentina. We collected data by means of a passive surveillance system that involved a network of researchers, field partners (veterinarians, park rangers, and local community), and decision makers. We sampled marsh deer during as well as outside mortality events. A total of 44 marsh deer with different body condition scores were evaluated. We obtained haematology and biochemistry values from animals with good body condition score. Marsh deer with poor body condition had a high burden of the ticks Amblyomma triste and Rhipicephalus microplus. Vector-borne agents such as Theileria cervi, Trypanosoma theileri, Trypanosoma evansi, Ehrlichia chaffeensis, Anaplasma platys, Anaplasma odocoilei, Anaplasma marginale, and Candidatus Anaplasma boleense were also found. Haemonchus spp., Ostertagia spp., and Trichostrongylus spp. were the most frequent gastrointestinal parasites in deer with poor body condition. A Multiple Correspondence Analysis reinforced a possible association of winter period with lower body score condition, high tick loads, infection with E. chaffeensis, and presence of harmful gastrointestinal parasites. CONCLUSIONS: Our approach allowed the establishment of a participatory surveillance network of marsh deer morbidity and mortality in Argentina. We report and analyse the first data obtained opportunistically within the framework of this network, providing information on the infectious and parasitic agents in marsh deer populations. The occurrence of Fasciola hepatica and Leptospira interrogans serovar pyrogenes is reported for the first time in wild marsh deer from Argentina. Our data will be useful to improve the interpretation of future mortality events. The field implementation of a surveillance network is key to a holistic approach to wildlife diseases.
Assuntos
Infecções Bacterianas/veterinária , Cervos , Doenças Parasitárias em Animais/parasitologia , Infestações por Carrapato/veterinária , Ferimentos e Lesões/veterinária , Animais , Argentina/epidemiologia , Infecções Bacterianas/microbiologia , Infecções Bacterianas/mortalidade , Fezes/parasitologia , Doenças Parasitárias em Animais/epidemiologia , Doenças Parasitárias em Animais/mortalidade , Dinâmica Populacional , Especificidade da Espécie , Infestações por Carrapato/epidemiologia , Infestações por Carrapato/mortalidade , Ferimentos e Lesões/epidemiologia , Ferimentos e Lesões/mortalidadeRESUMO
Copper deficiency is an important disease of cattle that produces several clinical signs and lesions, due to alterations in copper-dependent enzymes. One of the organs affected by this deficiency is the heart (falling disease), but nevertheless, these cardiac lesions have not been extensively studied in bovines. The aim of this work was to propose a possible pathogenic mechanism for cardiac lesions in cattle affected by copper deficiency. Because of the possible existence of oxidative distress caused by low levels of copper-zinc-superoxide dismutase and cytochrome oxidase, ultrastructural and histological lesions have been evaluated in the heart of bovines in which a Cu deficiency had been induced using high molybdenum and sulfur levels in the diet. Our results indicated that copper deficiency produces significant damage in myocardium with high levels of lipid oxidation and a significant reduction in copper-zinc-superoxide dismutase activity leading to an oxidative distress situation. However, cytochrome oxidase activity was not significantly reduced. Histological observation revealed a significant increase in the amount of connective tissue, enlarged basement membranes of myocytes, and numerous Anichkov cells, in the hearts of deficient animals. Ultrastructural observation showed a significant enhancement in the mitochondrial volume density, with presence of lesions such as swelling and cristae disruption. We conclude that copper deficiency in bovines causes morphological lesions in the heart due to an oxidative damage produced by copper-dependent enzyme alterations.
Assuntos
Cobre/deficiência , Coração/anatomia & histologia , Miocárdio/metabolismo , Miocárdio/patologia , Animais , Bovinos , Cobre/metabolismo , Masculino , Miocárdio/ultraestrutura , Estresse OxidativoRESUMO
Copper deficiency in humans and animals has been related to increased susceptibility to infections. Neutrophils are one of the most studied components of the immune response; however, to the best of our knowledge, other defenses of the innate immune system have not been analyzed in copper-deficient animals. Our previous studies in copper-deficient bovines have shown increased susceptibility to infectious keratoconjunctivitis, an ocular disease caused by Moraxella bovis. The objective of this work was to evaluate the bactericidal activity of lachrymal secretion and complement system, two main mechanisms of the innate immune response against M. bovis, in copper-deficient cattle. Our results indicate that copper deficiency has no effect on bactericidal activity of complement system and lachrymal secretion against M. bovis in calves. Other components of local and systemic ocular defense mechanisms that could explain the increased susceptibility to infectious keratoconjunctivitis observed in copper-deficient bovines should be investigated.