Cutaneous adverse drug reaction in a dog following firocoxib treatment.

A 9-year-old intact female toy poodle was presented with oedema around the neck, including pus and cutaneous necrosis, 2 days after starting firocoxib treatment and placement of a cervical collar for intervertebral disc disease. Cytology of the pus revealed predominantly mature neutrophils with fewer macrophages and lymphocytes, indicating sterile inflammation. Although a skin biopsy could have provided more diagnostic information, it was not performed at presentation. Firocoxib treatment was discontinued, and immunosuppressive therapy including cyclosporine was initiated, which significantly alleviated the skin lesions. The dog recovered fully in 7 weeks. The final diagnosis was a possible cutaneous adverse drug reaction to firocoxib based on history, clinical signs and response to therapy.