A nasal dermoid sinus in an English bull terrier.

A five-year-old, entire female English bull terrier was presented with a six-week history of intermittent facial swelling and nasal pain, following an incident of nasal trauma. A small opening was present at the mucocutaneous junction on the dorsal nasal planum. Examination under general anaesthesia allowed catheterisation of this opening and confirmed the presence of a tract passing caudally. Plain radiographic examination of the region was unremarkable. Positive contrast sinography demonstrated contrast material filling a midline tract that passed caudally and subcutaneously towards the nasal bone. This tract was surgically excised. Histopathological examination of the excised tissue, together with the clinical findings, led to the diagnosis of nasal dermoid sinus.