- Diseases of the external ear canal (otitits externa) of the horse are not as common as in small animals.
- Cause : several diseases, however, can cause ear disease.
- Primary causes of otitis include atopic dermatitis [Skin: atopy] , black fly bites, insect hypersensitivity, eg Culicoides , and ticks. Less commonly food allergy , Psoporptic mange and vasculitis have been reported to induce ear disease.
- Otitis externa secondary to otitis media has also been reported in horses and appears to have an insidious course.
- Signs : exudate, crusting, pruritus, ear rubbing, head tossing/weaving.
- Diagnosis : cytological examination of exudates, otoscopic exam, endoscopy.
- Treatment : fly control, food trials, anti-inflammatory drugs, antibiotics.
- Prognosis : depends on underlying cause.
- Depends on underlying cause.