Doenças do sistema nervoso central em bovinos no Sul do Brasil

Abstract

cslb@sm.conex.com.br A retrospective study was carried out on 6,021 necropsies of cattle performed over a 36-year period in southern Brazil. Of those, 552 (9.16%) presented neurological clinical signs and their necropsy protocols were reviewed to gather information on type of gross and histopathological diagnosis, etiology, and clinical signs. In 147 cases (26.63% of 552) there were no significant lesions in the central nervous system, in 79 (14.31% of 552) no samples of nervous tissue were submitted to the laboratory and in 21 (3.81% of 552) the tissues submitted were autolysed and not suitable for histological diagnosis. Lesions found in the remaining 305 cases were classified as inflammatory, degenerative, circulatory, congenital, and neoplastic. The inflammatory lesions accounted for the largest category (66.89% of 305 cases). This was further divided in lesions caused by viruses (57.38% of 305 cases) and by bacteria (9.51% of 305 cases). Diseases caused by viruses were rabies (49.51% of 305 cases), necrotizing meningoencephalitis by bovine herpesvirus (4.59% of 305 cases), and malignant catarrhal fever (3.28% of 305 cases). The degenerative changes were represented by 74 cases (24.26% of 305 cases) and included status spongiosus due to liver failure induced by Senecio spp poisoning (10.49% of 305 cases) or to the direct effect of poisoning by Ateleia glazioviana (0.33% of 305 cases); cases of liver failure not associated with morphological changes in the brain (2.95% of 305 cases), myelomalacia due to cord compression (2.62% of 305 cases), primary neuronal degeneration associated with Solanum fastigiatum poisoning (2.29% of 305 cases); polioencephalomalacia (1.97% of 305 cases); tetanus (1.31% of 305 cases) and intestinal coccidiosis in calves, ketosis, and botulism with one case each (0.33% of 305 cases). Circulatory disturbances accounted for 19 cases (6.23% of 305 cases) and included cerebral babesiosis (5.57% of 305 cases) and hemorrhages due to trauma (0.66% of 305 cases). Congenital conditions represented 2.29% of the 305 cases and included cerebelar abiotrophy (two cases) and one case each of porencephaly, hypomyelinogenesis, demyelination, hydrocephalus, and cerebellar malformation. Only one neuroectodermal neoplasm (0.33% of 305 cases) was found in this series.INDEX TERMS: Central nervous system, diseases of cattle, pathology.

Abordagem diagnóstica das principais doenças do sistema nervoso de ruminantes e equinos no Brasil

“…Os principais dados epidemiológicos e clínico-patológicos dessas doenças estão nos Quadros 1-4 e nas Figuras 1-18. Para uma descrição detalhada de cada doença o leitor pode acessar as publicações correspondentes às doenças de bovinos (Sanches et al 2000, Langohr et al 2003,b,c, Rodrigues et al 2005a, 2007, 2008b, Sant'Ana et al 2009a,b, Lucena et al 2010, ovinos (Rissi et al 2008a(Rissi et al ,c, 2010a, caprinos (Rissi et al 2006b) e equinos (Barros et al 1984, Rodrigues et al 2005b, Pierezan et al 2007). Como ocorre em qualquer sistema, para o diagnóstico das doenças do SN é necessário um histórico epidemioló-gico e clínico completo e, quando for o caso, uma completa descrição dos achados macroscópicos.…”

Aspectos epidemiológicos, clínicos e distribuição das lesões histológicas no encéfalo de bovinos com raiva

“…Considerando-se no diagnóstico apenas os achados histopatológicos de meningoencefalite não-supurativa, é necessário diferenciar a raiva das duas outras enfermidades infecciosas causadas por vírus que afetam o sistema nervoso central de bovinos no Brasil: encefalomielite herpesvírus bovino (BHV-5) e febre catarral maligna (SANCHES et al, 2000). Na infecção pelo BHV-5, as lesões histológicas consistem Figura 1 -Aspectos epidemiológicos e clínicos e distribuição das lesões histológicas no encéfalo de bovinos com raiva.…”

“…A raiva é a enfermidade infecciosa viral mais prevalente no sistema nervoso central em bovinos no Rio Grande do Sul (SANCHES et al, 2000). As lesões são geralmente limitadas ao sistema nervoso central (JONES et al, 1997).…”

Bovine herpesvirus type 5 (BHV-5) in a calf with rabies

“…Rabies is the most prevalent cause of central nervous system (CNS) disease in cattle in southern Brazil (Sanches et al 2000). Routine rabies laboratory diagnosis is based on direct fluorescent antibody testing (DFAT) and mouse inoculation (Murphy et al 1999).…”

“…This virus has recently been shown to be the second major identified cause of lethal encephalitis in cattle (Sanches et al 2000). In Brazil, the number of documented cases of BHV-5 encephalitis is increasing steadily, particularly in the regions Bovine herpesvirus type 5 The brain of an one year old male calf which died with signs of neurological disease was submitted to the laboratory for rabies diagnosis.…”