Polioencephalomalacia associated with closantel overdosage in a goat

Abstract

This report describes clinical and pathological findings associated with closantel (a halogenated salicylanilide anthelmintic) overdosage in a 3-year-old goat. The clinical signs included blindness, incoordination, ataxia, depression of the palpebral and pupillary reflexes, and recumbency. No gross lesions were noted in tissue or organs at necropsy, but microscopic lesions were seen in nervous tissue and hepatic cells. Polioencephalomalacia was clearly evident. Bilaterally symmetrical status spongiosus of the white matter of the brain, bilateral laminar necrosis, microcavitations, ischaemic cell change and severe degeneration of the cerebellum were seen in nervous tissue. Fatty change and hydropic degeneration in the liver and hepato-cellular degeneration were observed histologically

Retinopathy and optic neuropathy following closantel treatment of ewes

“…Serous atrophy of adipose tissue deposits has been described in goats, although this may be due to a period of anorexia before death or euthanasia, as was a multifocal yellow discolouration in the left middle liver lobe histologically consistent with hepatic necrosis (Ecco and others 2006). Similar gross findings were not reported elsewhere, though Sakhaee and Derakhshanfar (2010) found hydropic and fatty change and hepatocellular degeneration. No hepatic changes, apart from capsular fibrin tags and mild cholangitis, were noted in the two animals submitted for postmortem examination.…”

“…Status spongiosus of the white matter of the forebrain, as described in previous studies (Borges and others 1999, Ecco and others 2006, van der Lugt and Venter 2007, Sakhaee and Derakhshanfar 2010), was not seen in these cases. This may be due to the two-month interval between dosing and postmortem examination.…”

“…Previously, ataxia and recumbency have been reported (van der Lugt and Venter 2007). Depression has been described in both sheep (Borges and others 1999) and goats (Ecco and others 2006, Sakhaee and Derakhshanfar 2010) but may be difficult to differentiate from blindness. Opisthotonus and colic were described in goats (Ecco and others 2006, Sakhaee and Derakhshanfar 2010).…”

“…Depression has been described in both sheep (Borges and others 1999) and goats (Ecco and others 2006, Sakhaee and Derakhshanfar 2010) but may be difficult to differentiate from blindness. Opisthotonus and colic were described in goats (Ecco and others 2006, Sakhaee and Derakhshanfar 2010). Gill and others (1999) described only blindness and Barlow and others (2002) reported ataxia only in the lightest lamb (i.e.…”

A review of polioencephalomalacia in ruminants: is the development of malacic lesions associated with excess sulfur intake independent of thiamine deficiency?

“…Thiamine deficiency induced PEM has been reported in cattle, sheep, horses, dogs [6], goats [14], camels [15], and cats [16]. Thiamine deficiency in ruminants has be associated with several factors such as an impairment of microbial thiamine synthesis, thiamine destroying activity of bacterial thiaminase, along with other dietary factors involved in thiamine destroying activity in the rumen [17].…”