Dogs have acute hearing. They can hear very faint sounds, noises at high frequencies, and can detect even very slight changes in the tones of sounds.
Because of their acute sense of hearing, dogs rely on their hearing much more than on their eyesight in their day-to-day survival.
For dogs to hear properly, the sound-transmitting cells in the ears and the sound-interpreting cells in the brain must be intact and functioning normally.
There are several causes that can result in canine deafness. Let’s take a look at each of these causes below.
Causes and Types of Hearing Loss in Dogs
Some dogs are born without the ability to hear because, for some reason, their hearing apparatus is not well or fully developed.
Puppies usually can respond to sound around 11 days after birth, and you can check if your newborn puppies have congenital deafness after the 11th day.
Congenital deafness can affect one or both ears, so if your puppy is deaf in only one ear, it may be difficult for you to even notice the problem.
Interestingly, dogs with white or merle coats are predisposed to congenital deafness, with Dalmatians at the highest risk.
Dogs with “acquired deafness” are born with normal hearing capacity, but hearing is lost due to such factors as:
- middle and inner ear infections
- head traumas and injuries
- health problems such as hypothyroidism, tumors of the middle ear, and sometimes brain tumors
Certain medications can also cause deafness in dogs. For example, some antibiotics such as Gentamicin, Neomycin, Streptomycin, and Kanamycin can cause nerve damage resulting in hearing loss.
Most dogs with acquired deafness do not lose their hearing totally, but instead can still hear certain sounds, especially high-pitched ones.
Aging dogs gradually lose their hearing over time. Hearing loss usually begin at around ten years of age.
As in acquired deafness described above, most dogs with senile deafness do not lose their hearing totally. They can usually still hear sounds that are of a higher pitch (e.g. a whistle).
Symptoms and Diagnosis of Hearing Loss in Dogs
Dogs with mild cases of hearing loss can function relatively normally. Sometimes the owners do not even realize that their dogs have a hearing problem.
Dogs with significant hearing loss are less active and move more slowly and carefully. As they cannot hear, they fail to obey verbal commands. They may be startled if someone approaches and touches them from behind.
Hearing tests using an electroencephalogram (EEG) can be done to determine if a dog has hearing loss by a procedure called a brain stem auditory evoked response (BAER) test.
Normally, different sound frequencies invoke different brain waves which can be measured by EEG. If the brain wave pattern is unchanged, it means that the dog cannot hear the sound.
Coping with Hearing Loss in Dogs
Unfortunately, deafness cannot be reversed.
However, most dog parents are able to communicate well with their hearing-impaired dogs through hand signals, a whistle, or even signals using lights.
Don’t approach your dog from behind. As your dog cannot hear you approaching, don’t just walk up to him from behind and start petting him. He might be startled and might respond in an aggressive way.
A dog who cannot hear is more at risk when walking outside, as he cannot hear approaching cars, bicycles, and other people. Always put the dog on a leash and keep him close to your side.
If you and your family are vigilant and try to support your hearing-impaired dog, he will live a normal and happy life.