BAER (Brainstem Auditory Evoked Response) is a quick and non-invasive test that can diagnose deafness in dogs and cats.
For some breeds, congenital deafness (from birth) is more common. Some breeds carry a piebald gene associated with deafness. These breeds include Dalmatians, English Bull Terriers, Border Collies and cats which have white coats (especially those with blue eyes).
How Does The BAER Test Work
The test uses three small acupuncture needles placed under the skin:
- One in front of the ear
- One on top of the head
- One centrally on the forehead
These generally don’t hurt when placed.
A headphone is placed over the ear being tested that produces a sound wave in a pattern of ‘clicks’. This then generates a computer graph measuring brain wave response to the sound allowing us to assess the hearing.
Once both ears have been tested the computer will print the graph and certificate which will be signed for you to take away.
BAER Test Age
The youngest age the test can be performed at is 6.5 weeks for puppies and 8 weeks for kittens. This is because the ear canals are not open until roughly 12-14 days of age so sound waves cant enter the ear.
There is no upper age limit for the BAER test being performed.
The Auditory System
Sound waves enter the external ear, which travel down within the inner ear canal. The sound waves reach the eardrum which then begins to vibrate. These vibrations move into the middle ear causing the tiny bones (auditory ossicles) to vibrate.
The vibration waves move to the cochlea in the inner ear. Hair cells within the cochlea begin to move or ‘wave’ due to the change in pressure.
The cochlea is connected to the auditory nerve which then triggers an impulse that is registered by the brain.
There are different types of deafness that can affect dogs and cats:
- Unilateral deafness - hearing loss in one ear
- Bilateral deafness - hearing loss in both ears
- Age related deafness - progressive hearing loss related to age
BAER Test Results
In ‘normal’ hearing the BAER test graph will show a number of peaks and troughs which are displayed on the screen.
The BAER test can identify whether the animal is deaf in one ear (unilateral deafness) or both ears (bilateral deafness). There is no ‘partial’ deafness in these cases.
Unilaterally and bilaterally deaf dogs can make excellent pets, however if bilaterally deaf, correct specialist training is required.
It is unadvisable to breed from unilaterally or bilaterally deaf animals, as this may be passed down through generations.
What Do I Do If My Pet Is Deaf?
We offer a number of canine training sessions ranging from 'Puppy Obedience and Socialisation' through to 'Agility Training'. We also have a behaviourist who can help with any worries or concerns you might have.
Please feel free to discuss any worries with your hearing clinic nurse who will always be happy to provide any further advice you might require.
For puppies that fail their hearing tests we recommend 'Hear, Hear! A Guide to Training a Deaf Dog by Barry Eaton' as this can help you with any challenges that may arise.
To speak to someone regarding the BAER test, or to book an appointment, get directions or for prices please call 01332 678333 or email firstname.lastname@example.org
Other Test Performed Using The BAER Machine
As pets get older they begin to naturally lose their ability to hear, so stop listening or responding to verbal commands.
Instead of the BAER test another test can be performed to identify the point at which your pet is unable to hear - this test is known as the Threshold test. The test itself is performed using the BAER machine.
Each ear is tested several times using different volumes of the frequency. Each test is performed at 10 decibels lower than the previous test e.g. starting noise of 70db will decrease each time until roughly 20db to see at which point your pets hearing is affected.
When your pet is unable to hear the noise, the graph on the computer will remain flat or the peaks and troughs won’t be as clear.
Once the test is completed a graph and certificate will be printed and signed for you to take home.