Horse Ear Discharge: Infection, Mites or Injury?

Ear discharge usually means there is inflammation somewhere in or around the ear canal. In horses, one important cause is otitis externa, which means inflammation or infection of the outer ear canal. Discharge may look waxy, crusty, pus-like, or bloody. Some horses also shake their heads, resent having the ears touched, or develop a bad odor from the ear.

Mites are another real possibility. Merck notes that nonburrowing psoroptic mites can cause otitis externa in horses. These horses may have itching, head shaking, a drooping ear, crusted papules, scaling, or hair loss on the pinnae. Mites can be hard to find, so your vet may need skin scrapings or a sample of ear debris to confirm the cause.

Trauma is also common. Horses can cut or bruise the ear on fencing, bucket hardware, trailers, tack, or during rubbing and head shaking. A wound may ooze blood or infected fluid, and a painful swollen ear can quickly become contaminated with dirt and flies. Facial nerve injury can also cause a drooping ear, which changes how the ear moves and may make discharge more noticeable.

Less commonly, discharge-like material around the ear may actually be drainage from nearby structures or skin disease around the ear base. Because the ear connects with deeper structures, your vet may also think about middle ear disease, neurologic problems, or nearby upper-airway issues if your horse has head tilt, facial weakness, fever, or other concerning signs.

A small amount of dry surface debris on the outer ear flap may not be an emergency if your horse is comfortable, eating normally, and acting like themselves. Even then, true ear discharge is worth a scheduled exam because horses often hide pain, and mites or infection can worsen if they are missed.

See your vet the same day if the discharge is bloody, thick yellow or green, foul-smelling, or paired with marked pain, swelling, fever, head shaking, or a fresh wound. Prompt care also matters if your horse will not let anyone touch the ear, seems dull, or has flies gathering around the area.

See your vet immediately if you notice a head tilt, loss of balance, facial droop, trouble blinking, trouble chewing, feed dropping, or other neurologic changes. Merck notes that head tilt suggests vestibular dysfunction, and facial paralysis in horses can occur with inner ear or guttural pouch infection as well as trauma.

Do not try to deeply clean the ear at home. Probing the canal with cotton swabs or pouring in products can push debris farther in, increase pain, and make it harder for your vet to examine the ear safely.

Your vet will start with a physical exam and a close look at the outer ear, ear base, and surrounding skin. They will ask when the discharge started, whether your horse has been shaking their head, if there was recent trauma, and whether any products were already used. They will also look for clues such as crusting, odor, swelling, pain, facial asymmetry, or a drooping ear.

Many horses need a careful otoscopic exam to look deeper into the canal. If the ear is painful or the horse is anxious, sedation may be the safest option for both the horse and the team. Your vet may collect ear debris for cytology to look for inflammatory cells, bacteria, or yeast, and may do a skin scraping or otic sample if mites are suspected.

If infection is severe, recurrent, or not responding as expected, your vet may recommend culture and sensitivity testing to help choose medication. If there is concern for deeper disease, they may add bloodwork, radiographs, or referral imaging. In horses with nasal discharge, strangles history, facial nerve changes, or head tilt, your vet may also consider endoscopy of the guttural pouches or upper airway because nearby disease can affect structures connected to the ear.

Treatment depends on the cause. Options may include gentle ear cleaning performed by your vet, parasite treatment, pain control, wound care, topical medication, systemic medication, and follow-up exams to make sure the canal is improving.

Keep your horse in a clean area and reduce rubbing, fly exposure, and anything that could bump the ear. If there is visible drainage on the outer ear flap, you can gently wipe only the outside with clean gauze dampened with saline or warm water. Stop if your horse resists or seems painful.

Do not insert cotton swabs into the canal. Do not pour in peroxide, essential oils, alcohol, or leftover ear medications. These products can irritate tissue, hide the true appearance of the discharge, and make the next exam harder. If your horse has a wound, follow your vet's instructions closely for cleaning, fly control, and bandaging if bandaging is possible for that location.

Watch for changes twice daily. Call your vet sooner if you see more swelling, a stronger odor, thicker discharge, blood, fever, worsening head shaking, a drooping ear, head tilt, trouble blinking, or reduced appetite. Those changes can mean the problem is progressing.

Most importantly, give all medications exactly as directed and finish the full course unless your vet changes the plan. Ear problems often look better before they are fully resolved, so rechecks matter.