Hereditary deafness in bulldogs or any kind of dog is a condition characterized by the degeneration of the inner structures of the ear which are associated with the sensory nerve. The process of degeneration usually starts within a few weeks after birth however some puppies which have inherited the condition are already deaf when born.
Although it has been identified as a congenital disease, the mode of inheritance has not been fully established because it does not adhere to a specific pattern of inheritance. There have been various studies done to establish a possible correlation between genes for coat color and deafness.
The gene for hereditary deafness can be inherited from one (unilateral) or both (bilateral) parents. Most dogs suffering from unilateral cases live normal lives while those which have inherited the disease from both parents (bilateral) often manifest major behavior problems particularly when the owner is not willing to ‘walk the extra mile’ to train these dogs appropriately.
The first signs that will provide a clue that a puppy may be bilaterally deaf include sleeping deeply or playing roughly with their littermates. They often fail to hear the cries of his littermates thus they continue to play rough with them.
One of the ways to determine hearing defects is by observing a dog’s response to sounds made outside the dog’s line of vision or when it is sleeping. However, there are many factors which can influence the response of the animal thus results may be highly subjective thus limiting its reliability.
An electro-diagnostic testing is a better diagnostic tool for the assessment of auditory functions. A BAER (brainstem auditory evoked response) testing will help arrive at a definite diagnosis. This specialized equipment is often used by veterinary neurologists to diagnose hearing-related problems for it can be performed in awake or anesthetized dogs.
Being a congenital condition, there is no successful treatment for hereditary deafness. Dogs affected with the condition can have a better quality of life when they are able to receive proper training such as using hand signals. Proper training will also prevent these pets from developing undesirable behaviors.
Prevention is still the best way to prevent proliferation of hereditary deafness in dogs. It is highly recommended that dogs which are diagnosed to be affected bilaterally or unilaterally or are carriers of the trait should be removed from the breeding group.
Since hereditary deafness is common in many breeds of dogs, it is strongly recommended that Baer testing be done for all of these breeds particularly Dalmatians and English setters before they are bred.