Training and Caring for a Deaf Dog (cont.)

What causes dogs to go deaf over time?

Other causes of deafness later in life can include repeated or untreated ear infections, toxic chemicals and some drugs, aging, and injury, Strain says.

"I've seen a number of [Labrador retrievers] with hearing loss from guns being fired too close to their heads," he says.

Dogs that go deaf later in life seem to have little trouble adapting to their condition, Strain said.

"Usually, the owners are more upset by it than the dog," he says.

How can I tell if my dog is deaf?

If you suspect your dog might be deaf, try this test: wait until your dog is asleep or not looking at you and make a loud noise behind him, says Holly Newstead, who co-founded the Deaf Dog Education Action Fund in the mid '90s with her husband, John, after they acquired a deaf Dalmatian puppy.

"Make sure they can't see your movement, or feel any vibrations, like you stomping on the floor," Newstead says. "And try different ranges of sound. Blow a whistle for the high range, clap your hands loudly for mid-range, and hit a drum for low range. Many mostly deaf dogs still have some limited hearing."

And if your dog suddenly seems to be ignoring you, or doesn't come running when food is poured into his bowl, you might want to test his hearing as well, Newstead says.

Pet owners who want conclusive evidence can ask for a test called the Brainstem Auditory Evoked Response procedure, or BAER. During this test, electrodes are placed under the dog's scalp to read the brain's response to a series of clicks directed into each ear.