Presumed erlotinib-induced bilateral corneal ulcers in a dog with lung tumor

Objective: To report the corneal toxicity of erlotinib in dogs. Animal studied: A 13-year-old castrated male Maltese dog. Results: A dog with lung cancer presented with a month-long history of mucoid discharge and blepharospasm in both eyes. Corneal ulcerations with stromal thinning were diagnosed in both eyes, which were refractory after 2 weeks of treatment with topical antibiotics and artificial tears. The dog was orally administered erlotinib (Tarceva®) by his owner for 2 months to treat his lung cancer. Urgent withholding of erlotinib was recommended, and after 2 weeks of discontinuation, the corneal defects resolved; however, corneal thinning remained until the six-month follow-up. Conclusions: To the best of author's knowledge, this is the first report in the veterinary literature that describes bilateral corneal ulcers associated with erlotinib administration in a dog.