Manifestation of oculorenal syndrome in a dog chronically receiving zonisamide

Tubulointerstitial nephropathy and uveitis, otherwise more broadly known as oculorenal syndrome in human medicine, is a condition that has, to the authors' knowledge, not been described in veterinary medicine. This report describes an 8-year-old, male, neutered, mixed breed dog with a 6-year history of idiopathic epilepsy, chronically receiving zonisamide, who was presented for sub-acute and recurrent episodes of severe generalised weakness, altered mentation and inappropriate urination. Throughout the dog's hospital visits, recurrent anterior uveitis, progressive severe metabolic acidosis, proteinuria, persistent granular casts and severe renal tubular acidosis, which progressed to renal insufficiency, were evident. Due to a poor prognosis and perceived poor quality of life, the dog was humanely euthanased. Postmortem examination and histopathology revealed tubulointerstitial nephropathy. In conjunction with clinical uveitis, this presentation reflects similarities with the human oculorenal syndrome, here referred to as canine oculorenal syndrome suspected secondary to chronic zonisamide administration.