Is your dog conveniently deaf, or could he actually be hard of hearing?
You know the scenario: In the park, you call the dog, but he doesn’t take the blindest bit of notice and carries on playing…
It may be that your dog is enjoying his game so much that he isn’t tuned in to your shouts. But sometimes it isn’t lack of attention or poor recall training that’s to blame — some dogs genuinely don’t hear well.
A Familiar Scene
Has this ever happened to you? The dog is some distance away when you call. His head goes up and he looks around, puzzled, as though he thought he heard something, but he wasn’t sure.
Just as people can suffer from deafness, so can dogs. Indeed, their hearing is so much more sensitive than ours that dogs are at increased risk of noise-related damage.
Types of Hearing Loss
The most common type of hearing loss is caused by damage to the cochlea in the inner ear. The cochlea converts sound waves into electrical impulses via the movement of fine hairs in a special gel. It is these electrical impulses that stimulate the auditory (hearing) nerve to the brain, where they are decoded as sounds.
Exposure to loud noise causes permanent damage to these fine hairs (cilia). Over a dog’s lifetime, when enough hairs (or cilia) are damaged, the hearing is affected.
Another form of hearing loss is hereditary deafness. This is where genetics inherited from the parent dog code for hearing difficulties or total deafness. A staggering 60 breeds of dogs and cats are known to suffer from this. These include:
Certain coat colors are also associated with an increased risk of deafness. These include:
- Merle or extreme piebald coats in dogs
- Dominant white coat genes in cats
The deafness can be in 1 or both ears, be partial or complete — which is why a hearing test for pets can be useful.
The Behavioral Hearing Test
If you’ve ever knocked pan lids together to see if your dog hears, you’ve performed a behavioral hearing test. The idea is simple: Make a noise and see if the dog reacts to it.
Though simple, the idea is also flawed. To start with, you need to be careful that the dog doesn’t see you make the noise (or he might react to your action) or that any air moves his whiskers. A pet’s whiskers are incredibly sensitive to movement, and those pan lids can make quite a waft of air.
Another problem: This test gives you no information about whether the pet has a problem in 1 or both ears and if the problem is mild or moderate. It tells you only about that particular frequency of sound. Dogs hear a wide range of frequencies, from around 70 Hz to 65 KHz, so it’s possible they hear some sounds but not others.
The Brainstem Auditory Evoked Response (BAER) Test
This is the gold standard of dog hearing tests and is the same as that used on newborn babies. The dog can either have a brief “pass or fail” hearing test (used to screen very young puppies for deafness) or a full hearing exam, which takes 30 minutes.
The BAER works by monitoring the brain’s response to sounds the ears pick up. Think of it as throwing a stone into a pond, where the sound is the stone and the ripples are brain waves.
In a quiet room, the dog is played a number of sounds of different frequencies. Probes that measure electrical impulses in the brain are attached to the skin of the dog’s skull. If a sound is played and the brain doesn’t respond, then the dog has a problem hearing that frequency.
The BAER gives a full hearing assessment in the same way that a person with hearing difficulties might be tested by an audiologist. Unfortunately, the drawback is the expense, because the special equipment costs thousands of dollars and is therefore the purview of specialist centers or universities.
The Importance of Hearing
Although these tests may seem over the top for a regular pet, it’s great to know if a potential service dog has good hearing before investing time and money into training.
If you suspect your dog is hard of hearing, be sure to use hand signals in addition to spoken commands. In addition, keep him on a leash near roads, as he won’t hear a shouted warning if he runs into traffic.
This pet health content was written by a veterinarian, Dr. Pippa Elliott, BVMS, MRCVS. It was last reviewed Jan. 15, 2016.