Deafness in dogs

Deafness is quite common in dogs, particularly in older dogs and dogs with a white hair coat and blue eyes. Although deafness may cause a dog some problems most deaf dogs can be helped to live a happy life.

Deafness is quite common in dogs. Many breeds of dog, e.g. Dalmatians, Collies, Great Danes, English setters and Pointers, carry a gene that can cause deafness. This is often associated with a white or merle coat colour and blue eyes.

Deafness is also common in older dogs, probably due to age-related degeneration in the inner ear, as seen in older people.

Other reasons for deafness are long-term ear infections, growths in the middle ear or external ear canal and medications given by veterinary surgeons to treat these conditions. Head trauma and brain tumours are also potential causes. However, deafness can result from anything that damages the conduction of sound waves from the ear hole through the ear canal and ear drum to the bones of the middle ear or which affects the conduction of impulses through the nerves to the brain.

Deafness in one ear is not usually detected and actually causes few problems. If the affected dog is lying on one side with the good ear buried and the deaf one exposed then hearing would be impaired and an owner may notice a lack of response to noises. However, dogs who are deaf in one ear probably take care to avoid lying in such a position and generally keep their good ear pointing in the right direction, even when relaxed at home.

Being deaf in both ears causes more significant problems and most owners notice that their dog does not respond to noises – the opening of doors, the fridge, food packages, calling their name etc. and fail to respond to noisy people, animals and machinery. As puppies, deaf animals may be hard to train and may indulge in very rough play as they are unable to hear protest yelps.

Deaf dogs tend to “sleep well”. This is something that owners of older animals may notice as their pet’s hearing deteriorates with age. Owners of old dogs may notice that they now tolerate the noise of a vacuum cleaner, or fireworks when previously they did not – this may be the most obvious sign of growing deafness.

Hearing can be tested by observing the reaction the dog makes to a sudden, unexpected loud noise. A hearing dog is expected to turn its ears towards the noise, and may also move their whole head and possibly move their body into a more alert position.

There are problems with this test. It cannot detect deafness in a single ear, only a totally deaf animal will fail to react. It is also possible to think that a deaf animal can hear if, for example, it reacts to a visual clue if it sees an object being dropped or hands being clapped or it may be able to feel vibrations when something hits the floor.

The opposite might also happen – a well-adjusted, non-fearful and relaxed dog may react to a noise the first time it hears it but will quickly react less and less obviously to subsequent noises. This test will be easier to interpret in a dog well known to the owner in its normal environment.

The only truly reliable test is one similar to that used for the testing of hearing in humans and involves sophisticated equipment available only in a few centres. Your veterinary surgeon would be able to advise you of a centre that offers testing if necessary.

The test is well tolerated by most dogs but involves playing noises into each ear in turn and then detecting the nervous impulses invoked by these noises in the brain. It is called BAER (Brainstem Auditory Evoked Response) testing. This test will not be necessary for the vast majority of dogs with a suspected hearing problem as testing will not usually make any difference to the dog or how they are helped and managed.

Dogs with normal hearing use the sounds detected by both ears to accurately pinpoint sounds. A dog that is deaf in one ear may hear you calling when you are out for a walk but may not be able to locate where you are. They may look around wildly until they see your position before coming back.

The reduced ability to recognize danger is probably the most serious handicap faced by totally deaf dogs. A deaf dog cannot hear its owner when out for exercise and so there is a greater risk it will run across a busy road to see a dog on the other side. Further examples of dangerous noisy items are farm and garden machinery, household appliances and trains. Deaf dogs should not be allowed off the lead except in safe, enclosed spaces.

It is unlikely that there will be a treatment to help resolve the deafness in your pet. The most common causes – a genetic defect or age-related degeneration – have no appropriate treatment. It is only some of the unusual causes such as disease blocking the passage of sound through the external ear canal from infection, or a mass that can be removed by an operation that can be helped by treatment.

Dogs with these conditions will usually have other obvious signs of disease rather than deafness being the major problem. They will have ears that are dirty, smelly and irritating. They may scratch and shake their heads or might also have a head tilt. Other signs of underlying disease include wobbliness, from damage to the balance organs, which are also found in the inner ear.

Animals that are deaf in just one ear require no special treatment. A totally deaf dog can adapt well to living in a normal household. Since your dog cannot hear you, you may need to adopt a more tactile approach with them. Petting and stroking becomes a much more important form of contact when your dog can’t hear you praising it and deaf dogs might want more physical contact, especially when resting in the home to reassure them that you are near (whereas a hearing dog can lie in another room and still be aware of you moving around the house).

Training a dog that has been deaf from birth can be challenging but it is perfectly possible to do this using hand signals for commands. Choose hand signals that are clear and can be recognised from some distance away. ‘Stop’, ‘sit’ and ‘come’ are probably the most useful to teach initially. Dogs are also very good at reading body language so although they cannot hear your voice a deaf dog will be able to tell if you are angry with it or welcoming just by looking at you and it may base its decision on whether to return to you on this impression. It is important as in any dog training to remain calm and positive during training sessions – patience really is the key!

Some dogs are more likely to be deaf so avoid buying puppies from litters where both parents have a merle or harlequin coat. Some puppies from these matings may be born blind as well as deaf.

Deafness causes significant welfare problems and breeders should aim to avoid producing puppies likely to be deaf. However, individual deaf dogs can be given a reasonable quality of life by thinking about their special needs. Deafness (or reduced hearing ability) is also quite common in older dogs and considering this is one aspect of providing a good home for a geriatric companion.