Deafness in Horses

While deafness in horses is rare, there appears to be certain genetic predispositions that may indicate a higher risk of deafness. Deafness can be partial or full, meaning your horse may react to sudden loud noises, but struggle to hear everything. However, on the other hand, he may not react to any noise and you may notice he is easily startled due to not being able to rely on his hearing.

While deafness will change your horse’s life, it does not mean he is not capable of living a fulfilling one. There are 3 common causes of deafness in horses: trauma, infection, and congenital. 

If your horse is becoming deaf, you may notice a change in his behavior. He may no longer respond to verbal cues; he may tilt his head and exhibit abnormal gait, among many other possible symptoms. These symptoms can mimic injury, neurological conditions, cysts and more so it will be important to look for more specific symptoms.

Deafness in horses is rare, but does happen. You may notice that your horse does not react to sudden noises and spooks easily. There may be partial or full deafness as well in your horse.

Symptoms vary greatly from horse to horse when deafness is present. 

• Altered behavior 
• Becoming easily startled when they weren’t before
• Not responding to verbal cues when they once did
• Difficulty with training
• Leaning to one side – if there is an inner ear balance problem your horse may lean his head to one side 
• Head tilt – this may also happen in the event of inner ear/balance problems your horse is experiencing 
• Head shaking – if your horse is suffering from an infection, he may shake his head along with rubbing his ears to try and comfort himself
• Abnormal gait – you may notice your horse have difficulty when it comes to walking or trotting with no explanation 
• Corneal ulceration
• Dysphagia

Types

There are 2 types of deafness your horse can experience.

Partial 

• He may react to sudden or loud noise
• Struggles to hear verbal cues or normal sounds

Full 

• Your horse may not react to any auditory cues

The 3 main causes of deafness in your horse stem from trauma, infection and congenital defects. 

Trauma 

• Most often caused while the horse is in his stall or at the gate
• Head injuries can result in deafness in horses

Infection or Inflammation 

• In the event your horse develops an infection of his ears and it is left untreated, this could result in deafness as well
• Inflammation of the ear can also result in deafness
• Some medications used to treat infection may be ototoxic 

Congenital

• Certain horses are predisposed to have deafness; however it is not a guarantee that all horses with these qualities will be deaf : American paint horses, horses with white spotting, horses with blue eyes 
• Congenital malformations of the ear and bones can result in deafness

If your suspect your horse is suffering from deafness, a visit with the veterinarian will be necessary to identify the underlying cause of his symptoms. It will be important to identify and share with the veterinarian if your horse has recently experienced any injury or trauma that could be the cause of his symptoms.

Your veterinarian will want to perform a neurological exam as well. This exam will help to determine more signs and symptoms that your horse may be suffering that could lead towards a differential diagnosis of deafness. Once the exams are complete, testing will be necessary.

Two of the tests typically done for this condition are the BAER (brainstem auditory evoked response) test and the click test. The BAER test is the primary test used to diagnose deafness and tests the auditory pathways. This test is noninvasive and safe for your horse. The click test is done using earphones that produce clicks that activate fluid in the ear, and test if it activates signals in the brain or not. In addition, your veterinarian may want to do an endoscopic exam to view and evaluate the ear structure.

Treatment options will be based on the underlying cause of your horse’s deafness. In the event of infection, medication may be prescribed to eliminate the cause. However, if the event is trauma or congenital, there may not be any way to correct the damage done to your horse’s hearing. If the cause is an ototoxic medication, cessation of the drug may resolve a temporary deafness.

It may be a matter of working with your horse on his new adaption to the world around him. Treatment will revolve around training and working with your horse’s abilities rather than trying to correct the hearing loss.

Follow up appointments will only be necessary if your horse has been injured or required any type of medical intervention. If your horse developed deafness later in his life and was already trained, it will be easier to work with him on adapting. Once you are aware of your horse’s deafness it will be easier to work with him and help his adjust through physical or visual cues rather than verbal cues.

It is very possible for your horse to still train, perform and show with some adaption on both of your parts. It is important to remember he may easily startle and remember to approach him where he can see you so he is not alarmed.