Source: AAHA
A case report in Frontiers in Veterinary Science details toxic effects after a 4-year-old Labrador retriever ingested a 60 g tube of 1.5% ruxolitinib (Opzelura®), a human topical Janus kinase (JAK) inhibitor. JAK inhibitors treat inflammatory and autoimmune skin diseases in people but can be highly toxic to pets. The dog consumed approximately 21 mg/kg and presented 6–8 hours later with lethargy, bilateral ptosis, sinus tachycardia, and markedly decreased tear production. Laboratory findings included mild neutropenia, elevated lactate, and slightly increased liver enzymes.
During hospitalization, she developed sinus bradycardia. Treatment consisted of intravenous fluids, sedation, analgesia, nutritional support, and ocular therapy. After 25 hours of supportive care, she was discharged, and clinical signs fully resolved. Toxicologist Renee Schmid, DVM, emphasized that toxicity is dose-dependent and can be fatal, warning against a “wait and see” approach. The report highlights possible mechanisms involving cytokine dysregulation and stresses rapid intervention, careful monitoring, and safe medication storage to prevent accidental exposures.