Polioencefalomalacia em caprinos e ovinos na região semi-árida do Nordeste do Brasil

Abstract

Seven outbreaks of polioencephalomalacia in goats and 3 in sheep are reported from the semiarid region of northeastern Brazil. Animals of different ages were affected in various seasons of the year. In 5 outbreaks the animals were supplemented with concentrate ration and in 5 others they were only grazing on pastures. In one outbreak sheep were supplemented with an energy-protein-mineral mixture containing 1.3% of sulfur flower. Clinical signs were characterized by blindness, depression, head pressing, circling, grinding of the teeth, incoordination, spastic paralysis, ataxia, depression of the palpebral and pupillary reflexes, lateral strabismus, nystagmus, and dilated pupils. Nine affected animals were treated with thiamine and dexamethasone; 7 of them recovered but 2 died. The diagnosis of the disease was based on the recovered animals after treatment and/or on the histologic lesions. The clinical course varied from 2 to 15 days. On three animals post-mortem examination was made. One had herniation of the cerebellum through the Foramen magnum and softening of the cerebral cortex. The cut surface of the cerebral cortex showed cavitation and yellowish discoloration. Another animal had only cerebellar herniation. In a third animal no gross lesions were observed. Histological changes in the 3 animals were laminar necrosis of the cerebral cortex, and in 2 malacia of the thalamus and the rostral colliculi was also observed. In 9 outbreaks the cause of the disease was not determined, but one was probably due to sulfur toxicosis caused by the high sulfur content of the energy-protein-mineral mixture containing 1.3% of sulfur flower (96% sulfur) and 30% chicken litter (0.39% sulfur).

Polioencephalomalacia in ruminants from the semi-arid region of Rio Grande do Norte, Brazil

“…Excluding this case, the morbidity ranged from 8.1 to 30.7%, which is a range close to that reported in the other outbreaks. The case-fatality rates described in the literature ranged from 48.5-100% (NAKAZATO et al, 2000), 50-100% (SANT 'ANA et al, 2009a;RIBAS et al, 2013), and 66.6-100% (LIMA et al, 2005), is similar to those obtained herein. Results of CSF analysis showed a density above the physiological parameters or in the upper limit for four cases.…”

“…In Brazil, PEM is predominant in cattle (NAKAZATO et al, 2000;LEMOS et al, 2004;VIEIRA et al, 2007;CUNHA et al, 2010CUNHA et al, , 2011RIBAS et al, 2013), although there are also reports in sheep (LIMA et al, 2005;VIEIRA et al, 2007;DUARTE et al, 2014), goats (LIMA et al, 2005), and in buffaloes (GUIMARÃES et al, 2008).…”

Doenças do sistema nervoso central em caprinos e ovinos no semi-árido

“…O surto em caprinos e um dos surtos em ovinos foi descrito por Lima et al (2005b). O segundo surto de PEM ocorreu em maio de 2005, em um rebanho de 300 ovinos da raça Santa Inês, dos quais adoeceram e morreram 9 animais.…”

Sinais clínicos, distribuição das lesões no sistema nervoso e epidemiologia da raiva em herbívoros na região Nordeste do Brasil

“…Essa variação dos sinais clínicos faz com que a raiva possa ser confundida com outras doenças freqüentes do sistema nervoso central de pequenos ruminantes. Na região semi-árida as doenças mais freqüentemente observadas em pequenos ruminantes são a polioencefalomalacia (Lima et al 2005), os abscessos cerebrais e os traumatismos. A polioencefalomalacia, por causar sinais cerebrais, assim como sinais cerebelares e do tronco encefálico pode ser facilmente confundida com casos de raiva com lesões predominantes cerebrais, como as do Caso 1.…”