BAER Testing for Deafness

BAER testing is a test formulated to detect hearing and deafness in dogs, and measure deafness that is either acquired or present from birth. The acronym BAER stands for Brainstem Auditory Evoked Response, and it measures the brain’s electrical activity as a response to sounds-usually clicks played as part of the test.

The BAER test is widely accepted as the most reliable way to definitively diagnose total deafness in dogs, and the differences in their hearing in each ear. However, the test only evaluates sounds within the human hearing range-and some dogs that are tested deaf may still be able to hear very high noises that fall outside of the range of human hearing.

Whilst the BAER test can be used to test deafness and hearing in any dog, whether their hearing issues are hereditary and present from birth or not, it is usually used to test the hearing of breeds that have heightened risk factors for hereditary deafness, such as the Dalmatian, and certain variants of other breeds that come with a heightened risk of deafness, such as the merle coat pattern in collies.

In this article, we will look at BAER testing for deafness in more detail, including why your dog might need to be tested, when the test should be performed, and how to interpret the results. Read on to learn more.

Why might your dog need to undergo BAER testing?

If your dog comes from a breed that has a higher than usual incidence rate of hereditary deafness such as the Dalmatian, BAER testing is usually advised in order to identify the hearing status of the litter before they go off to their new homes.

Additionally, dogs suffering from hereditary deadness or hearing problems are likely to pass the condition on to their offspring, and so identifying deafness in adult dogs is important, so that they can be removed from the potential breeding pool.

Even if your dog has no history of deafness in their breed line and is not from a high risk breed, if you know or suspect that they are losing their hearing for any reason, finding out the full extent of the problem via BAER testing can help to ensure that you manage the condition properly.

Full or partial deafness has lots of implications for affected dogs and their owners, including the need to adjust your training and management of them accordingly, and understanding that they may miss potential hazards, such as the sound of traffic coming.

When should dogs be tested?

Dogs can be BAER tested at any age, and there is a lot of merit in having older dogs tested in order to develop a full understanding of their limitations and abilities.

However, as the BAER test is mainly designed to identify hereditary deafness in dogs from at-risk breeds, the test is usually performed on puppies before they reach an age at which they will be sold or rehomed.

Testing should not be performed on very young puppies, as pups are born deaf and their ear canals do not open fully until at least the age of two weeks old.

Generally, the recommended age for initial testing is between five and seven weeks of age, which also ties in with the activity patterns of pups at that age, who are apt to go through short bursts of high activity, followed by deep sleep, which is a good time to perform the test.

How is the test performed?

BAER testing is performed by measuring the electrical responses of the brain when the ears are exposed to sound, and because the test relies on the presence or absence of sound-triggered electrical brain activity, the test is much more accurate and conclusive than simply trying to assess the dog’s hearing by means of their responses to sound stimulus.

To have your dog or litter BAER tested, you will need to take them along to a specialist veterinarian that has the equipment and qualifications to perform the test, and details of the centres that can carry it out are contained within this section of The Kennel Club website.

Interpreting the test results

Once the test has been performed, the results are returned in a very simple form, as outlined below:

• Bilaterally affected: The dog is totally deaf in both ears.
• Unilaterally affected: The dog is totally deaf in one ear, but has normal hearing in the other one.
• Unaffected: The dog has normal hearing in both of their ears.

However, the test cannot tell you about partial deafness in either ear, or if your dog’s hearing is not completely normal-only whether or not each ear can hear at all, with the results given in binary form as either totally deaf or able to hear.

An unaffected dog’s hearing will still fall somewhere on a scale from perfect hearing to partial hearing, and this is something that dog owners need to determine by other means.