DEAFNESS IN DALMATIANS

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 Dalmatians are one of several breeds of dogs that are prone to deafness. This is due to the "extreme piebald" gene- the gene responsible for the high white content in a dog's coat. But, the presence of this gene by itself is not sufficient to cause deafness. All Dalmatians have two copies of the extreme piebald gene, but only about 20-30% are deaf, so there are other genes at work in how this extreme gene presents itself. 

As of now, there is no test to identify the other genes responsible for the expression of extreme piebald to cause a dog to be deaf, but there are steps that can be taken to greatly reduce the chance of producing deaf puppies. 

These include: 

• Never breeding a bilaterally OR unilaterally deaf dog
• Not repeating breedings where there is a significant amount of or repeating pattern of producing deaf puppies
• Not breeding dogs with blue eyes or heterochromia
• Not breeding dogs with a history of deafness in their pedigree

Any reputable breeder should have Dalmatian puppies tested for hearing impairments before they are placed in homes. This is done by taking the pups to a specialized veterinarian that will perform what is known as a BAER (Brainstem Auditory Evoked Response) test. This is quick and painless, and the puppies do not need to be anesthetized. This test places electrodes on the puppy and checks for electrical activity in the dog's auditory pathway as a response to playing clicking noises in the dog's ear. The results are then printed out and if the ear is hearing, you will see a nice, spiked waveform in the chart. If the ear is non-hearing, you will see a straight or almost straight line where the waves should be. 

A BAER test can only be performed by a specialized vet. If your potential breeder tells you that their normal vet said that the puppies can hear fine, this is a major red flag. Vets or practices that offer this specialized test are few and far between. There is also an ideal time window to test puppies. Done too early, the test can have inaccurate results. It can cost a breeder hundreds of dollars and several hours of travel to take each litter to be tested during the appropriate time period for accurate results. But this is a critical factor of an ethical practice, and breeding for improvement. 

No! While this breed does have a higher predisposition to inherit deafness, this does not mean that all or even most Dalmatians are deaf. In fact, less than 30% of Dalmatians have a hearing impairment, with only ~8% of that number consisting of completely deaf dogs. Selective breeding and ethical practices have proved to continue to put this number on the decline.

Deafness in Dalmatians is a congenital condition. This means it is present from birth and not curable. If a dog is going to be affected by this, it will be present and noticeable from very early on, and will not change.  This means an experienced breeder should have a pretty good idea of whether or not a pup has a hearing impairment, even before they have them tested. This also means that if a pup does come back as having unilateral hearing (deaf in one ear), the condition will not change or "spread", so there is no chance of them losing hearing in their normal ear, except by injury or old age.  

The only thing different about a unilateral dog from the outside perspective is that sometimes their directional hearing is compromised. Other than that, a unilateral dog will live a completely normal life, and most times you will never notice that they are impaired at all. 

Unilateral dogs should always be placed in a pet only home. While a reputable breeder will provide a copy of their BAER test to the new owner and be transparent about the results, the dog is not any "worse" than a normal pet quality puppy, and will live a completely normal life. This is why I will choose not to denigrate the value of a unilateral dog as a normal pet when placing them in an appropriate home by reducing the price.

There has not been any data showing that gender or color has a higher risk for deafness, even in lemon colored dogs. There is however, data that shows that dogs with blue eyes, heterochromia, or who are unilaterally or bilaterally deaf DO produce higher numbers of deaf dogs. It has been shown that dogs with patches have a lower chance of being deaf than non-patched dogs, but this does not coincide with amount of spotting, since the heavier or lighter a dog's spotting pattern will be is determined by a different gene completely than the piebald gene.