Spinal cord compression in cattle after the use of an oily vaccine / Compressão medular em bovinos após o uso de vacina oleosa

ABSTRACT

An outbreak of compressive myelopathy in cattle associated with the improper use of an oil vaccine is described. Neurological signs were observed in 25 out of 3,000 cattle after 60 days of being vaccinated against foot and mouth disease. The clinical picture was characterized by progressive paralysis of the hind limbs, difficulty in standing up, and sternal recumbency during the course of 2-5 months. A filling defect between the L1 and L3 vertebrae was seen through myelography performed in one of the affected animals. A yellow-gray, granular and irregular mass was observed in four necropsied animals involving the spinal nerve roots and epidural space of the lumbar (L1-L4) spinal cord; the mass was associated with a whitish oily fluid. This fluid was also found in association with necrosis of the longissimus dorsi muscle. Microscopic changes in the epidural space, nerve roots, and spinal musculature were similar and consisted of granulomas or pyogranulomas around circular unstained spaces (vacuoles). These spaces were located between areas of severe diffuse hyaline necrosis of muscle fibers and resembled the drops of oil present in the vaccine.

RESUMO

Relatamos um surto de mielopatia sas medulares e espaço epidural da região lombar (L1-L4); compressiva lombar em bovinos associada à aplicação de esse material era associado com líquido brancacento e vacina oleosa de forma inadequada. De um total de 3000 oleoso. Havia também áreas de necrose no músculo Lonbovinos, 25 apresentaram distúrbios neurológicos apro-gissimus dorsi com material similar ao do espaço epidural. ximadamente 60 dias após terem sido vacinados contra a Microscopicamente, as alterações observadas no espaço febre aftosa. O quadro clínico foi caracterizado por parali-epidural, raízes nervosas medulares e na musculatura fosia progressiva de membros posteriores, dificuldade para ram similares sendo caracterizadas pela formação de múlpermanecer em estação e decúbito esternal com evolução tiplos granulomas ou piogranulomas envolvendo espaços de 2-5 meses. A mielografia realizada em um animal reve-(vacúolos) circulares não corados (aparentemente, o local lou defeito de enchimento na altura das vértebras L1 e L3. antes ocupado por gotículas de óleo presente na vacina), Quatro animais foram necropsiados e foi visualizado massa além de necrose hialina severa difusa de fibras musculares.