Equine neural angiostrongylosis

Abstract

Verminous encephalomyelitis due to Angiostrongylus cantonensis larvae was diagnosed in 2 foals at necropsy. The principal clinical feature was tetraparesis, although history and neurological examination revealed progressive and multifocal neurological disease. At presentation, a tentative diagnosis of parasitic larval migration involving the central nervous system (CNS), presumably due to Strongylus vulgaris, was proposed. Dissection of the spinal cord in one case resulted in recovery of intact larvae of both sexes of A. cantonensis. In both foals, histopathology of the brain and spinal cord revealed nematode sections which were consistent with A. cantonensis larvae.

Emergence of Neural Angiostrongyliasis in Eastern Australia

“…Apart from rats and dogs, A. cantonensis has also been reported in many different animal species in Australia, including captive Bennett's wallabies (Macropus rufogriseus) (McKenzie et al 1978), horses (Wright et al 1991), captive rufous bettongs (Aepyprymnus rufescens) (Higgins et al 1997), captive tamarins (Sanguinus spp.) (Carlisle et al 1998), wild black-and grey-headed flying foxes (Pteropus species) (Barrett et al 2002), Yellow-Tailed Black Cockatoos (Calyptorhynchus funereus) (Monks et al 2005), and, most recently, Tawny Frogmouths (Podargus strigoides) (Monks et al 2005, Gelis et al 2011, Ma et al 2013) and brushtail possums (Trichosurus vulpecula) (Ma et al 2013).…”

Parasitic Infection of the Central Nervous System

“…Angiostrongylus cantonensis has been described in two foals in Australia. 25 Clinical signs included a "dog-sitting" posture and inability to rise in one, and ataxia followed by recumbency in the other. Treatment of one foal with ivermectin was attempted, yet progression of clinical signs was rapid, and both foals were humanely destroyed due to the severity of their clinical condition.…”

The vestibular system. Part II: Differential diagnosis

“…Signs of central vestibular dysfunction have been attributed to the effects of migration of metazoan parasites through the brain stem of mature horses (Mayhew et al 1982). Various parasitic species have been implicated in equine cerebrospinal nematodiasis including: Halicephalobus gingivalis (Micronema deletrix), Strongylus vulgaris, a filariid parasite, Setaria spp., Hypoderma bovis, Hypoderma lineatum, Draschia megastoma and Angiostrongylus cantonensis (Powers and Benz 1977;Frauenfelder et al 1980;Mayhew et al 1982;Darien et al 1988;Wright et al 1991;Costa et al 2000;Kinde et al 2000). However, antemortem diagnosis of cerebrospinal nematodiasis in mature horses is difficult.…”