Suspected sulfasalazine‐induced acute hepatic necrosis in a dog after one year of continuous treatment

Abstract

AbstractAn 18‐month‐old male entire golden retriever presented with inappetence and a 12‐hour history of episodic vomiting. The dog had been receiving sulfasalazine 15 mg/kg twice daily for one year for the treatment of lymphoplasmacytic colitis, which was well controlled prior to presentation. The dog had no history of other drug or toxin exposure. Investigations initially revealed raised liver enzymes, which increased during hospitalisation along with development of neutropenia and thrombocytopenia. During hospitalisation, acute hepatic necrosis was diagnosed histologically, and the dog recovered completely with supportive treatment and discontinuation of the sulfasalazine. The hepatic necrosis was believed to be associated with a toxic‐metabolite dependent idiosyncrasy due to the long‐term use of sulfasalazine. Unlike other cases previously reported, this dog developed these clinical signs after one year of treatment rather than immediately after therapy initiation. This may raise awareness about possible late‐onset reactions when using long courses of sulfonamides.