Apparent tick paralysis in a cat from North America.

Case Summary: A 2-year-old castrated male domestic longhair cat presented for acute, diffuse, flaccid paralysis. Thoracic and abdominal radiographs, biochemistry panel and complete blood count were unremarkable. Titers to , myasthenia gravis radioimmunoassay testing and creatinine kinase levels were within normal limits. The most likely differentials included acute toxicity (coral snake envenomation, organophosphate toxicity), botulism and, less likely, acute polyradiculoneuritis. A thorough physical examination revealed a single engorged tick attached to the ventral neck of the cat, which was later identified as an adult female species. Topical fipronil and -methoprene was administered. Over the next 48 h, the cat recovered full motor function and at 5 days post-tick removal the cat had resumed all normal activities.

Relevance And Novel Information: Tick paralysis is considered endemic in Australia by bites from, most commonly, the tick. However, this phenomenon is rarely reported in the USA. This is the first report of a domestic cat suffering from acute tick paralysis in North America.