Abstract
A 27-year-old Shetland mare was examined for persistent coughing, increased respiratory rate and mild exercise intolerance. Over the previous 5 months, the mare had experienced a persistent cough nonresponsive to medical and environmental management. Upon endoscopic examination of the lower airways, a mass was seen within the left mainstem bronchus; biopsy identified a granular cell tumour. The tumour was successfully reduced by repeated transendoscopic diode laser photoablation over a period of 4 months with no evidence of recurrence at 10 months post treatment.