Doenças neurológicas de pequenos ruminantes no Nordeste do Brasil

• Autor(a) principal: OLIVEIRA, Juceli de Souza
• Data de Publicação: 2019
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFRPE
• Texto Completo: http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/8228
• topic: Neuropatologia; Doença neurológica; Caprino; Ovino; CIENCIAS AGRARIAS::MEDICINA VETERINARIA

Understanding the mechanisms that determine the neurological diseases of small ruminants is essential to arrive at the diagnosis and consequent treatment, reducing the economic losses to goat-sheep farming. Due to the importance of neurological diseases for goat and sheep farming in the northeast region, this study aims to present a comprehensive review of the literature on neurological diseases of small ruminants and to describe in two unpublished scientific papers the epidemiological, clinical and pathological aspects of tremorgenic syndrome in sheep associated with the consumption of Ipomoea asasifolia and the enzootic ataxia associated with secondary copper deficiency in goats. The outbreak of tremorgenic syndrome associated with the consumption of Ipomoea asarifolia in suckling lambs occurred in the Metropolitan Region of Recife, State of Pernambuco. Eight Dorper lambs infants whose mothers had access to a pasture invaded by I. asarifolia were affected, 60% of the adult animals including the lactating ewes showed only engorged episcleral vessels; lambs presented clinical neurological signs characterized by head and neck tremors, dysmetria, increase in the base of support, lateral gait, abnormal posture and imbalance followed by falls, these signs were less intense and became more evident when the lambs were moved. Three lambs with mild clinical signs recovered after receiving cow's milk from the bottle. Five lambs died and were necropsied and there were no macroscopic changes. The histological lesions consisted of axonal spheroids in the molecular layer of the cerebellum, presence of numerous eosinophilic neurons and retracted in the cerebral cortex and cerebellum. This work demonstrates that Ipomoea asarifolia causes tremorgenic syndrome and its toxins are eliminated by milk and that younger animals are more susceptible to intoxication compared to adults. In relation to enzootic ataxia in goats, an outbreak was investigated in the Agreste of Pernambuco. In a herd for goat farming, approximately 80% [155/194] of the herd presented clinical signs characterized by lethargy, progressive weight loss and acromotriquia. Seventeen goats presented clinical neurological signs, five of them immediately after birth, where the main clinical signs evidenced were depression, ataxia, flaccid paralysis of the pelvic limbs and death. The mean values of copper in goats were 6.15 μmol / L and in kids, 5.78 μmol / L, which were lower than those considered normal for goats. The main histological lesions consisted of degeneration and loss of Purkinje neurons in the cerebellum associated with Bergmann cell proliferation. Neurons of the medulla oblongata and some nervous ganglia presented central cytoplasm and cytoplasmic hyalinization. In the gray matter of the cervical, thoracic and lumbar portions of the marrow, motor neurons with the eosinophilic cytoplasm, diffuse scintigraphy and peripheral nuclei were observed. In the medullary white matter there was axonal degeneration, characterized by the presence of vacuoles, sometimes organized in chains containing occasionally macrophages or cell debris. The diet offered to the herd contained adequate amounts of copper, so it is suggested that an excess of iron intake from residues from a pottery neighboring the property of the occurrence of the outbreak could have caused the lack of copper in the animals.