Adverse drug reactions to Zonisamide in two dogs.

We report two dogs with Zonisamide adverse drug reactions. Case 1, a 6-year-old, intact, female Maltese presented with erythroderma, and case 2, a 10-year-old, castrated, male miniature Pinscher showed erythema multiforme-toxic epidermolytic necrolysis. Both cases were suspected of having adverse drug reactions to Zonisamide based on their symptoms, blood test results and histopathologic findings. The eruptions completely disappeared with cessation of Zonisamide. A lymphocyte transformation test was carried out on both cases, but no positive reactions were seen. Further investigation of adverse reaction to Zonisamide, especially its incidence and pathogenesis, with more cases will be needed.