## Overview Trigeminal neuritis is inflammation of the trigeminal nerve (cranial nerve V), which supplies the muscles of mastication. It may occur with polyneuritis equi or idiopathically. Bilateral atrophy of the masseter and temporalis muscles produces a sunken face, and the horse may be unable to close the mouth (dropped jaw), leading to difficulty eating and weight loss. ## Causes Nerve inflammation, idiopathic or associated with polyneuritis equi. ## Diagnosis Clinical signs of bilateral masticatory muscle atrophy and dropped jaw. Further testing for polyneuritis equi if indicated. ## Treatment Supportive care, including assisted feeding. Corticosteroids are sometimes used. Recovery is variable. ## Recovery and Prognosis Guarded. Some horses improve. Others have permanent deficits. ## Prevention None.
bilateral masseter and temporalis atrophy (sunken face); inability to close the mouth (dropped jaw); difficulty eating; weight loss
## Overview Trigeminal neuritis is inflammation of the trigeminal nerve (cranial nerve V), which supplies the muscles of mastication. It may occur with polyneuritis equi or idiopathically. Bilateral atrophy of the masseter and temporalis muscles produces a sunken face, and the horse may be unable to close the mouth (dropped jaw), leading to difficulty eating and weight loss. ## Causes Nerve inflammation, idiopathic or associated with polyneuritis equi. ## Diagnosis Clinical signs of bilateral masticatory muscle atrophy and dropped jaw. Further testing for polyneuritis equi if indicated. ## Treatment Supportive care, including assisted feeding. Corticosteroids are sometimes used. Recovery is variable. ## Recovery and Prognosis Guarded. Some horses improve. Others have permanent deficits. ## Prevention None.
bilateral masseter and temporalis atrophy (sunken face); inability to close the mouth (dropped jaw); difficulty eating; weight loss