Tick toxicity in cats caused by Ixodes species in Australia: a review of published literature

Abstract

Tick toxicity in cats caused by Ixodes holocyclus and related species is a common medical condition on the east coast of Australia. Intoxication typically causes a flaccid ascending neuromuscular paralysis and clinical signs can include anxiety, dysphonia, hind limb weakness and/or ataxia, pupillary dilation, respiratory signs and possible bladder voiding dysfunction. Diagnosis is made with a combination of appropriate clinical signs and visualisation of tick(s) on a thorough body search. Cases are classified clinically using a scoring system, which grades neuromuscular weakness and respiratory compromise. The mainstays of treatment are tick removal, administration of tick antitoxin serum and intensive supportive care. Given a prompt and appropriate management regimen, prognosis is good, according to available literature. Most of the literature concerning tick toxicity in cats is anecdotal in nature and an evidence-based review of what is known of this condition has not previously been published.

Fig 1.

The life cycle of the Australian paralysis tick, Ixodes holocyclus, includes three hosts and multiple moult cycles. The long-nosed bandicoot and the cat may each serve as hosts during the life cycle. Musca and Gunew (2004) reproduced with permission from Frank Gaschk (2007).