Veterinarians don’t really feel horses have a lot of ear problems but because of the difficulty in examining the ears of some horses, ear problems may be more plentiful than we think.  I try to examine the ears on every horse I examine or vaccinate and some of them will just not allow the ear exam without sedation.  Many owners will say that the horse has always been that way and just does not like the ears touched, and that may be correct as it may be a behavioral issue.  However, it is also possible the horse does not want the ears examined because there is a problem in the ears and the only method to find out is to look.  I am not suggesting every horse be sedated for an ear exam but if the horse is head shy or does not like the ears touched, it should at least be considered.  

One problem even with a sedated horse is the ear speculums used for dogs generally are not long enough to visualize the entire ear canal of the horse as the canal is not straight in to the ear drum but makes an acute angle, so the ear drum is hard to see.  A recent paper out of Germany indicated that it is effective to use an endoscope, which most equine vets have in their practice, to look inside the ear canal.  The advantage is the endoscope is flexible and allows the vet to look further in the canal.  The most common cause of ear disease in Texan horses is ear ticks and these can lead to serious problems and infection.  However, the study using the endoscope found that lots of horses with head shaking and vestibular disease also had ear infections that had not been diagnosed.  Some horses had foreign bodies in their ears that lead to shaking and infection and sensitivity.  So, if your horse does not like the ears examined, it may just be your horse.  However, it could also be a problem in the ears that needs to be treated.