Not every dog with too much white is deaf, so there are probably additional genetic factors which determine whether the dog is deaf. However, if breeders make efforts not to produce puppies with white on or close around the ears they can significantly reduce the frequency of deafness in the breed.
Most double merles with white on or around the ears are deaf, usually in both ears. Occasionally, Aussies that are not double merles who have these markings will be deaf in one or both ears. The deafness is caused by lack of pigment in the inner ear.
Although many dogs with white ears will be deaf, many deaf dogs have colored ears as well. Hearing loss affecting both ears equally is called Bilateral Deafness. A bilaterally deaf dog is completely deaf, or deaf in both ears. Hearing loss occurring on, or affecting only one ear, is called Unilateral Deafness.
Some dogs begin to lose their hearing at a young age, and certain breeds of dog are more susceptible to becoming deaf. Dalmatians, German Shepherds, Australian Shepherds, and Boston Terriers are just some of the breeds that are known to be more genetically predisposed to deafness.
Dogs that carry the piebald gene (affects the distribution and amount of white color) are often affected by deafness. Piebaldism is the result of the absence of melanocytes, the cells that create the pigment melanin.
Deafness in Dogs
More than 30 breeds of dogs have a known susceptibility for deafness, including the Australian shepherd, Boston terrier, cocker spaniel, Dalmatian, German shepherd, Jack Russell terrier, Maltese, toy and miniature poodle, and West Highland white terrier. Typically, it is more common in senior dogs.
While merle (especially blue merle with tan points) is associated with Australian Shepherds, it can occur in Border Collies as well. Merle Border Collies are often confused with Aussies for that reason. If you want to tell the breeds apart, look at their features in addition to their coloring.
Australian Shepherds are known to be one of the most intelligent dog breeds recognized by the American Kennel Club, and are renown for their obedience, agility, and excellence in herding and other active sports.
Despite their high energy, Aussies are usually quiet. They may bark to alert their owners of a stranger or an unfamiliar situation but other than that, you won't hear much from them.
The BAER (Brainstem Auditory Evoked Response) test is used to check the hearing of a dog. The test checks if the brain responds to noise (usually a clicking sound) and is a reliable way to see if a dog is deaf and to what extent.
Living with deafness may take some time to get used to—usually for the human more than the dog! Dogs who become deaf, especially later in life, typically do not experience any anxiety over their loss of hearing and seem to have very little trouble adapting to their condition.
Why are some Aussies deaf? The most common cause of deafness in Aussies is a lack of melanocytes (pigment cells) in the inner ear. These cells help translate air vibrations caused by sound into electrical impulses that travel to the brain. If the cells are absent, the dog will be deaf.
Aussies with mostly white coats can be produced when two merles are bred together. Merle is the patch-work coloring (black and grey or liver and buff) most associated with the breed. When a puppy inherits two copies of the gene for merle, it will usually have a lot of white in its coat.
The only way to effectively test a dog's hearing is through a Brainstem Auditory Evoked Response (BAER) test, which evaluates the components of the external ear canal, middle/inner ear cavities, cranial nerve and selected areas of the brainstem.
White Aussies are rare today because we have been slowly eliminating the “more white” forms of the white marking genes from our gene pool by not breeding Aussies with more than allowable white (though the preference for white trim on the show dogs does have some pushing the envelope.)
Australian Shepherds are known for their fierce loyalty with one person, that doesn't mean every Shepherd will act like that. Some Shepherds might not build a particularly strong bond with any one family member. Others might like one of you more than another, but they don't sit on you to show it.
Your Aussie will bond to his family and be protective of and loyal to them. Many dog owners are surprised to learn that even though Aussies have strong guarding and herding instincts, they are sweet and cuddly indoor dogs that can even be kept in apartments.
Aussies can be very clingy. They crave human companionship and love being included in pretty much everything you do, including being involved in all family activity. Since they require an active lifestyle, they will want to join in everything and anything that is going on around them.
Australian shepherd colors and patterns can vary greatly, but the United States Australian Shepherd Association recognizes these four major categories: black, red, red merle, and blue merle (merle being the genetic pattern that occurs in a dog's coat, often appearing as speckled patches of color).
Final Thoughts. Australian Shepherds aren't the best guard dog out there – but they aren't the worst either. Their caring nature and intelligence make them easy to train as protective dogs. However, they lack a lot of the oomph that some other breeds have.
In fact, a dog without hearing can be even more loving, as he has learned to rely on his other senses. He will stick closer to you so that he can see your movements and snuggle up close so that he can feel your closeness. Never let deafness in your dog discourage you.
Generally, it is fairly straightforward to determine if a dog is deaf. Puppies who are deaf may seem slow to learn; they do not respond to their names or pick up verbal commands. Older dogs with acquired deafness may sleep through your arrival home from work.
If you suspect your pet is losing her hearing, test her by calling her name or making a loud noise when she is looking away from you. Try several different levels in the tone of your voice because some dogs may be able to hear a higher or lower pitched sounds. Age related hearing loss can't be prevented.