Outbreak of enzootic ataxia in goats and sheep in the state of Bahia / Surto de ataxia enzoótica em caprinos e ovinos no estado da Bahia

The objective of this study was to describe for the first time the clinical-epidemiological, laboratory and pathological aspects of different forms of enzootic ataxia in goats and lambs in the state of Bahia, as well as to propose an emergency oral treatment with copper sulfate in an individualized way for neonates. Three outbreaks of enzootic ataxia were studied. The history, clinical signs and epidemiological data were obtained from the owners and checked during the visits. The first outbreak (FO) occurred in 2013 in a property located in the municipality of Itaberaba and affected a herd composed of 90 goats and 130 sheep. The second outbreak (SO) occurred in 2014 in the municipality of Santa Luz and affected a herd of 90 goats and 110 sheep. The third outbreak (TO) occurred in 2018, in a property located in the same municipality of the SO, being the herd constituted by 80 sheep. Samples of blood were collected from all goats and sheep treated for serum copper dosage. Nine animals (five goats and four sheep) that presented a more severe clinical picture and unfavorable prognosis were necropsied for diagnostic confirmation. During the necropsy of the FO, SO and TO animals, liver samples were collected for copper dosage as well as fragments of several organs for histopathology. At the site where the SO occurred, samples of soil and the main forages where the animals were kept were collected to determine copper, iron, molybdenum, sulfur and zinc contents. The clinical and histopathological findings in the three outbreaks studied were characteristic of enzootic ataxia. In the outbreaks studied, the frequency of enzootic ataxia was higher in goats (52) than in lambs (39). In the goats the mean values of serum copper (0.05mg/kg) and hepatic (2.48mg/kg) of the FO and SO were well below their respective reference values, 12 times lower than serum levels and eight times lower in relation to liver contents. On the other hand, TO sheep presented mean values of serum copper (0.015mg/kg) reduced by 40 times. The levels of iron and sulfur were high in the fodder of the property where the SO occurred, already in the soil, iron levels were high and copper levels were reduced. The treatment tested in neonates and lambs with two doses of copper sulphate solution orally at a dose of 20mg/kg for sheep and 35mg/kg for goats during the first and second week of life was effective in prevention of enzootic ataxia in neonates and can be used for emergency control of the disease. The occurrence of enzootic ataxia (congenital and late form) in goats and sheep was first reported in Bahia. It is also worth noting that this disease caused by copper deficiency has caused great damage to the breeders of small ruminants, mainly due to the high mortality of the animals affected.(AU)

Objetivou-se com esse estudo descrever pela primeira vez os aspectos clínico-epidemiológicos, laboratoriais e patológicos de diferentes formas de ataxia enzoótica em cabritos e borregos no estado da Bahia, bem como propor um tratamento oral emergencial com sulfato de cobre de forma individualizada para neonatos. Foram estudados três surtos de ataxia enzoótica. O histórico, sinais clínicos e dados epidemiológicos foram obtidos com os proprietários e verificados durantes as visitas técnicas. O primeiro surto (PS) ocorreu em 2013 em uma propriedade localizada no município de Itaberaba e acometeu um rebanho composto por 90 caprinos e 130 ovinos. O segundo surto (SS) aconteceu em 2014 no município de Santa Luz e afetou um rebanho formado por 90 caprinos e 110 ovinos. O terceiro surto (TS) ocorreu 2018, em uma propriedade localizada no mesmo município do SS, sendo o rebanho constituído por 80 ovinos. Amostras de sangue foram colhidas de todos os caprinos e ovinos atendidos, para dosagem de cobre sérico. Nove animais (cinco caprinos e quatro ovinos) que apresentavam quadro clínico mais grave e prognóstico desfavorável foram necropsiados para confirmação diagnóstica. Durante a necropsia dos animais do PS, SS e TS amostras de fígado foram coletadas para dosagem de cobre, bem como amostras de diversos órgãos para exame histopatológico. Na propriedade onde ocorreu o SS, foram coletadas amostras de solo e das principais forragens onde os animais eram mantidos, a fim de se determinar os teores de cobre, ferro, molibdênio, enxofre e zinco. Os achados clínicos e histopatológicos verificados nos três surtos estudados foram característicos de ataxia enzoótica. Nos surtos estudados, a frequência da ataxia enzoótica foi maior em cabritos (52) do que em cordeiros (39). Nos caprinos os valores médios de cobre sérico (0,05mg/kg) e hepático (2,48mg/kg) do PS e SS encontravam-se muito abaixo dos respectivos valores de referência, sendo 12 vezes menor em relação aos níveis séricos e oito vezes menor em relação aos teores hepáticos. Já os ovinos do TS apresentavam valores médios de cobre sérico (0,015mg/kg) reduzidos cerca de 40 vezes. Os teores de ferro e enxofre encontravam-se elevados nas forragens da propriedade onde ocorreu o SS, já no solo, os níveis de ferro apresentavam-se elevados e os de cobre reduzidos. O tratamento testado nos cabritos e borregos neonatos, com duas administrações individualizadas com solução de sulfato de cobre, por via oral, na dose de 20mg/kg para ovinos e 35mg/kg para caprinos, na primeira e segunda semana de vida, foi eficaz na prevenção da ataxia enzoótica nos neonatos e pode ser utilizado para controle emergencial da doença. Comprovou-se pela primeira vez na Bahia a ocorrência da ataxia enzoótica (forma congênita e tardia) em caprinos e ovinos. Ressalta-se ainda que, esta doença causada por deficiência de cobre, tem cursado com grandes prejuízos aos criadores de pequenos ruminantes, sobretudo, devido à alta mortalidade dos animais acometidos.(AU)

Swayback in a blesbok (Damaliscus dorcas phillipsi) and a black wildebeest (Connochaetes gnou).

Ataxia associated with myelopathy and low liver copper concentrations is described in a blesbok (Damaliscus dorcas phillipsi) and black wildebeest (Connochaetes gnou) from the Karoo Nature Reserve, Graaff-Reinet. This syndrome, which occurs in neonatal and delayed forms, has been described in sheep, goats, pigs and domesticated red deer, but reports in other ungulates, including antelope, are very rare and generally unconfirmed by histopathological examination. The 2 animals examined exhibited a typical pattern of Wallerian degeneration in selected tracts of the spinal cord. Many blesbok in the reserve are markedly pale in colour. Fading of the hair is also associated with copper deficiency in ungulates. High lamb mortality occurs as a result of the ataxia and threatens the survival of the blesbok herd in the reserve. Confirmation of low liver copper concentrations in affected animals offers direction towards the solution of the problem.

Studies on viral leukoencephalomyelitis and swayback in goats.

Six kid goats with CNS disease were studied by a variety of techniques. All had morphological evidence of Viral Leukoencephalomyelitis of Goats. (VLG) characterized by demyelinating encephalomyelitis and pneumonitis. Attempts were made to isolate a virus from 5 of these goats by direct culture of CNS and visceral tissues. Syncytial formation was found in some lung, spleen and bone marrow cultures but syncytia were found to be free of complete virus by electron microscopy. When newborn goats were inoculated with syncytia forming cells, a visna-like virus was found in bone marrow cultures of 1 goat 8 days post inoculation. Bone marrow cells from a twin goat 3 months after inoculation produced syncytia without complete virus. it is suggested that complete virus might be present in goats shortly after infection, while persisting in an incomplete form. Three of the 6 goats studied also had lesions of swayback with diffuse encephalomyelopathy and low liver copper levels. Control copper levels in kids with non-neurological disease were variable, occasionally being as low as swayback animals. The experience of others that swayback in the goat and low copper status are poorly correlated is confirmed. Discrepancies inherent in assaying formalin preserved tissues for copper are described.

Swayback (enzootic ataxia) in Alberta lambs.

Swayback (enzootic ataxia), a disease not previously described in Canada, occurred in newborn lambs in Alberta in 1972. Of 100 lambs born in one flock, over 60 succumbed in the enzootic. The diagnosis was based on the presence of a) gross cavitations and gelatinous lesions of the cerebral white matter in 16 of 24 (66.67%) lambs examined, b) central chromatolysis and hyalinization of neurons of the red and vestibular nuclei and reticular formation and of the lateral and ventral horns of the spinal cord, c) myelin deficiencies of the dorsolateral and sulcomarginal funiculi of the spinal cord and d) low hepatic and serum copper levels in affected lambs and low serum copper levels in the ewes. The feeding of sugar beet-(beta saccharifera) top silage to the ewes during pregnancy, lambing and lactation, and its relationship to the enzootic is discussed.