BAER testing is a hearing test for dogs that measures electrical activity in the brain in response to sound. It stands for Brainstem Auditory Evoked Response, and it’s the only objective way to confirm whether a dog is deaf in one or both ears. The test is quick, painless, and commonly used to screen breeds prone to congenital deafness.
How the Test Works
During a BAER test, three small needle electrodes are placed just under the skin: one on top of the dog’s head, one near the base of the ear being tested, and a ground electrode on the neck. These needles are thin enough that most dogs barely react to them.
Once the electrodes are in place, a series of clicking sounds is delivered into one ear through a small earphone. The clicks are played at around 95 decibels, roughly the volume of a lawnmower. Meanwhile, the opposite ear receives a low-level white noise to prevent it from picking up the test signal. The computer records the brain’s electrical response to each click. Because individual responses are tiny, the system averages around 1,000 clicks together to filter out background brain activity and isolate the specific signals traveling along the auditory pathway.
A normal result produces a characteristic waveform with several distinct peaks, each representing a different point along the path from the ear to the brainstem. A deaf ear produces a flat line with no recognizable peaks.
What It Can and Can’t Tell You
BAER testing gives a clear yes-or-no answer about whether each ear can detect sound. It tests each ear independently, which is critical because unilateral deafness (hearing loss in just one ear) is impossible to detect through behavior alone. A dog that’s deaf in one ear will still respond to sounds, turn toward noises, and seem perfectly normal to its owner. Only BAER testing can catch it.
The test does have limits. It primarily uses click stimuli, which test a broad range of frequencies at once rather than isolating specific pitches. This means it’s excellent at detecting complete deafness but less useful for identifying partial hearing loss or problems limited to a narrow frequency range. It also can’t tell you the cause of the deafness, only that it exists.
When Puppies Can Be Tested
Puppies need to be at least 6 weeks old for BAER testing. Before that age, the auditory pathways haven’t finished developing, and results are unreliable. Most breeders of at-risk breeds schedule testing between 6 and 8 weeks, before puppies go to their new homes. This timing gives buyers reliable information about the dog’s hearing status.
Breeds Most Commonly Screened
Congenital deafness affects more than 100 dog breeds, but the risk is highest in breeds that carry the piebald or merle coat color genes. Breeds with especially high rates of hereditary deafness include Dalmatians, Australian Cattle Dogs, English Setters, Bull Terriers, Dogo Argentinos, Catahoula Leopard Dogs, English Cocker Spaniels, Boston Terriers, and Parson Russell Terriers. In most of these breeds, the deafness results from loss of specialized hair cells in the inner ear within the first few weeks of life, linked to a lack of pigment-producing cells in that area.
Some breeds experience a different type of hereditary deafness that develops later in life. Border Collies and Rhodesian Ridgebacks, for example, can develop hearing loss in midlife. DNA testing exists for certain genetic forms of deafness in Rottweilers and Doberman Pinschers, but for the vast majority of breeds, BAER testing remains the primary screening tool.
Why Breeders and Buyers Care
A dog with bilateral deafness (both ears) requires specialized training and management. These dogs can live full, happy lives, but they need visual cues instead of voice commands and must be kept safe from hazards they can’t hear, like approaching cars. Responsible breeders want to identify bilaterally deaf puppies early so they can place them in homes prepared for their needs.
Unilaterally deaf dogs typically function well as pets with no special accommodations. The bigger concern with unilateral deafness is breeding. Because congenital deafness is hereditary, dogs deaf in one ear carry the genes for the condition and can pass it to offspring. Many breed clubs recommend that unilaterally deaf dogs be removed from breeding programs, making BAER testing an essential part of responsible breeding in high-risk breeds.
Sedation, Duration, and Cost
Most adult dogs tolerate BAER testing without sedation. The electrodes cause minimal discomfort, and the test itself takes only a few minutes per ear. Puppies tested in a litter setting are often calm enough to sit through it. Some dogs, particularly anxious or fidgety ones, may need light sedation because muscle movement creates electrical interference that can corrupt the recordings.
BAER equipment is specialized and expensive, so the test isn’t available at every veterinary clinic. You’ll typically find it at veterinary teaching hospitals, neurology specialty practices, and some larger general practices. UC Davis, for example, runs a hearing test clinic and charges $163 for the BAER test plus $33 for exam and sedation if needed, totaling around $196. Prices vary by location but generally fall in the $100 to $300 range. Breeders with full litters can sometimes arrange group testing sessions at a reduced per-puppy rate.
Results are immediate. The veterinarian can read the waveform printout right after the test and tell you on the spot whether each ear is hearing normally. Many facilities provide a certificate documenting the results, which breeders include with puppy sale paperwork or submit to breed registries.