Deafness in horses can result from inflammation, trauma or be genetically inherited.  Deaf horses often develop heightened perceptions of their other senses such as sight and smell, but may be startled easily.

Your horse's detailed case history is important to investigate what's causing suspected deafness because there may be many contributing factors.

Hearing tests for horses using brainstem auditory evoked response known as BAER testing can be easily and safely performed at many university veterinary teaching hospitals.

This information was adapted from an article by UQ lecturer and equine veterinary specialist Dr Allison.J.Stewart BVSc(hons), MS, DACVIM, DACVECC for Hoofbeats magazine. Read the article.