Reprodução experimental de doença ósseo metabólica em jacaré do Pantanal (Caiman yacare) : aspectos clínicos e patológicos

• Autor(a) principal: Moraes, Luiz Gustavo de
• Data de Publicação: 2015
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFMT
• Texto Completo: http://ri.ufmt.br/handle/1/718
• topic: Caiman yacare; Pantanal Matogrossense; Osteodistrofia fibrosa; Hiperparatireoidismo nutricional secundário; CNPQ::CIENCIAS AGRARIAS::MEDICINA VETERINARIA; Brazilian Pantanal; Nutritional hyperparathyroidism; Fibrous osteodistrophy

The commercial breeding of the swamp alligator (Caiman yacare) is an legal and alternative activity in the region of the River Paraguai (Mato Grosso, Pantanal) that prohibits the illegal hunting, preserves the species and has recognized the economic potential for agribusiness and brings positive social impact to family farming. In captivity, a major problem for the maintenance of the species are the nutritional diseases associated with badly formulated diets. The bone-metabolic diseases (DOM) are common in captive reptiles and commonly defined as a range of disorders affecting bone integrity and function. This group is common to fibrous osteoarthritis (osteitis fibrosa cystica), a relatively common metabolic disorder characterized by extensive bone resorption, accompanied by proliferation of fibrous tissue and the formation of cysts, often the rapidly formed mineralized osteoid not become forming immature bone. From the epidemiological investigation that included the occurrence of diseases, provided diets and management commonly adopted, the DOM often reported in farms alligator-swampland was reproduced in order to characterize the clinical and pathological picture. The study was conducted at the Veterinary Pathology Laboratory, LPV-UFMT, young alligators from the marsh, aged approximately three months, which were weighed, measured and randomly divided into four groups. Two diets were used, and a balanced high phosphatemic another, each associated with withdrawal and exposure, both supplied five times a week for six months. The disease was accompanied by clinical, radiographic and biometrics monthly assessment for body mass parameters and snout-vent length, throughout the experimental period. At the end of that period, the alligators were euthanized and samples were collected for histological studies, through eosin staining and hematoxylin and Masson's trichrome. The results obtained from the monthly biometrics, showed that high phophatemic diet was significant for negative effect on the snout-vent length, weight gain and caused clinical manifestation of the disease. There was no significant changes in relation to exposure to solar radiation or deprivation. The DOM has developed insidiously, becoming more evident between the 3rd and the 6th month after the start of the experiment. Affected animals showed pain when handled, severe muscle weakness, loss of appetite, cachexia in some cases, difficulty of movement and marked bone softening (rubbery consistency), 10 particularly of mandible and maxilla and particularly the thoracic and lumbar kyphosis. There was also moderate enlargement of the parathyroid glands. Radiography showed diffuse decrease in skeletal density, cortical thinning and angular deformations of long bones, particularly the spine. Microscopically was noted parathyroid cells hypertrophy characterized by moderate increase in the cytoplasm, decreased eosinophilia and occasionally vacuolization. The long bones (femur and tibia), flat (skull and jaw) and vertebrae, had marked osteoclastic bone resorption, with variable deposition of fibrous connective tissue and irregular increase in osteoblastic activity with immature bone formation. The clinical, leading to disease itself and the low growth rate attributed to metabolic bone disease, were morphologically classified as fibrous osteodystrophy, related to secondary hyperparathyroidism nutrition.