Immune‐mediated polyarthritis and anterior uveitis secondary to zonisamide administration in a dog with refractory epilepsy

The objective of this article is to describe a case of suspected zonisamide‐induced immune‐mediated polyarthritis (IMPA) and anterior uveitis in a dog. A 7‐year‐old male neutered Siberian Husky with a history of refractory idiopathic epilepsy was presented for cluster seizures. Following the addition of zonisamide to the antiepileptic regime, the dog developed new IMPA and anterior uveitis. Within a few weeks of discontinuation of the zonisamide, the dog's IMPA and anterior uveitis resolved. These immune‐mediated conditions were thus presumed to be an idiosyncratic reaction to zonisamide. To our knowledge, this is the first report of IMPA and anterior uveitis in dogs associated with zonisamide administration at its recommended dose. A dog with refractory seizures was presumed to have developed immune‐mediated polyarthritis (IMPA) and anterior uveitis secondary to zonisamide administration. Symptoms began shortly after the initiation of zonisamide and completely resolved within 2 weeks of discontinuation. Diagnostics did not reveal any other causes.