by Carin Smith, DVM
Your horse leans into your hand as you scratch just below its ear. You laugh as the horse’s weight nearly pushes you over. When you finish the horse shakes its head for a few moments. Is it just your imagination, or has your horse been shaking its head more often lately?
Then you notice a bald spot below the ear where your horse has rubbed the hair off from scratching against the fence post. Your horse has always liked being scratched, but this time you wonder if something is bothering its ear. Could there be something inside the ear?
Causes
Insect pests cause many of the minor problems you see with your horse’s ears. The first thing you may notice is the horse shaking its head or rubbing its ears to relieve an itch.
Flies, ticks and ear mites can all irritate the horse’s ears. Black flies are the culprit that cause the scabs you often see on the inside of the ear.
Other causes of head shaking include problems with the teeth, the ears, or the bit. Allergic horses with nasal irritation will also shake to the one side or walk in circles. With its balance so affected the horse has great difficulty walking.
Head tilt can be a sign of general nervous system disease or of an inner ear problem. Inner ear infection occurs as an extension of infection in the outer ear or guttural pouch. Sometimes no signs are noticed until the head tilt begins.
Another cause of sudden head tilt is a fracture of one of the bones near the ear. The fracture causes inflammation around the nerves that supply the middle and inner ear. Most horses with this problem do not experience severe head trauma.
Instead, it is thought the problem initiates with a middle ear infection that spreads to the bones. Over time the bones remodel and fuse into abnormal positions. The horse’s normal chewing and swallowing motions eventually cause the fracture.
A Closer Look
If your horse is shaking its head or rubbing its ears, take a closer look. Shine a flashlight into the ear and search for ticks or signs of fly bites.
Smear the inside of the ear with petroleum jelly for protection from black flies. Soak a cloth with fly spray and wipe the horse’s head and ears to ward off the pests.
Use a face net with attached ear coverings to keep flies away. Since black flies are daytime feeders, it may help to stable your horse during the day and let it out at night.
Fly spray will deter ticks, too. Check your horse’s ears for ticks frequently if you do much trail riding or if your horse grazes in a tick-infested area.
To remove a tick, use tweezers or forceps to grasp it gently as close to the horse’s skin as you can. Pull straight out. There is no need to kill the tick by burning it or applying anything to its body.
Don’t worry if you think you haven’t gotten the tick’s head out. The head will usually fester out on its own. Apply antibiotic ointment and observe the area for swelling. Call your veterinarian if you suspect infection.
Extra treatment for tick bites is not recommended in Lyme disease areas. That is because only a small portion of ticks carry the disease and there is a very low chance of your horse contracting the disease.
Most ticks in your horse’s ear are ear ticks, not the ticks that carry Lyme disease. Your best prevention against Lyme disease is to keep your horse protected with tick repellent and to remove ticks as soon as you find them.
Diagnosis
No matter what you suspect your horse’s problem to be, chances are you will need a veterinarian’s help to find out the precise cause of your horse’s distress.
Your veterinarian can look into your horse’s ear with an otoscope to see if a tick is deep inside. Long forceps are used to gently extract the tick.
If no tick is found, specimens taken with cotton-tipped swabs can be examined microscopically for evidence of ear mites or bacterial infection. Sometimes radiographs of the head are necessary if an internal or middle ear infection is suspected.
Other ear problems don’t cause irritation in the ear itself. For instance, a lump near the base of your horse’s ear may be the first sign of a tooth problem. A dentigerous cyst is a remnant of a tooth that is growing in the wrong place.
These cysts are congenital problems that may not be noticed until they begin to swell. As the tooth remnant grows it creates a fluid-filled swelling near the horse’s ear. Sometimes a sore opens and drains. The fluid develops because the horse’s body is reacting to the misplaced tooth the same way it would react to a sliver or other foreign body.
Dentigerous cysts that are not draining or causing another problem can be left as they are. Most should be surgically removed, though, since they tend to grow or to continually open and drain.
Simply lancing the cyst to allow the fluid to drain is not sufficient. Without removing the tooth remnant the problem will recur.
Difficulty of the surgery depends on exactly where the cyst is located. There is a greater risk of problems when a cyst is located close to the ear or to brain tissue. The entire cyst structure and the tooth remnant are surgically extracted.
Hearing & Deafness
Deafness is a rare problem in horses. Deafness may be congenital or acquired. Trauma, infection, or reactions to certain drugs can cause deafness. The horse may be partially or fully deaf and the problem may temporary or permanent.
Deaf horses may still be useful if special precautions are taken. It is important to avoid putting the horse in situations where its lack of hearing could put the horse or people in danger.
Some deaf horses may be more likely to inadvertently strike out when surprised because they didn’t hear a person approaching. People working around a deaf horse must take care to let the horse know where they are at all times.
How can you tell if a horse is deaf? You can do a simple but not completely accurate test yourself. Stand around a corner where your horse cannot see you and make a sudden, loud noise.
A friend should stand next to the horse and watch its response. Don’t just stand behind or to the side of the horse since it still could see you out of the corner of its eye.
Most horses will at least perk up their ears and look toward the sound. Try using different kinds of noise at different pitches, since partially deaf horses may be able to hear noises at a higher pitch.
Use anything from a whistle to a clap of your hands. The noise must be sudden and unexpected or the horse may not react.
Chances are your horse will never develop an ear problem. Rather than taking the ears for granted, though, now you can appreciate your horse’s ears and hearing ability.
