PROBABLE TRIGEMINAL NERVE SCHWANNOMA IN A DOG

A 7-year-old male Husky dog developed atrophy of the right masseter mu scle and pruritis of the right side of the face. A myogenic origin was excluded using muscular biopsy. Electrophysiologically, there was inv olvement of the motor and sensory fibers of the trigeminal nerve, sugg esting a lesion located between the brainstem and the trigeminal gangl ion. On MRI examination, a nodular mass was detected in the right caud al fossa. This mass was characterized by intense enhancement after inj ection of contrast medium. Because of the progressive clinical signs, electrophysiology, and MRI results, a presumptive diagnosis of a trige minal nerve schwannoma was made. The animal's condition improved sligh tly with corticosteroids. The dog underwent euthanasia 3 months after initial presentation. Necropsy was not performed.