The Dalmatian's deafness

by DOMINIQUE VINCENT, veterinary surgeon

    Summary: Because of intervention of several interacting genes, we will yet have to wait a few years so that genetic research at least places at our disposal a blood test which will bring an invaluable help for the choice of the reproducers. But this blood test will not be categorical, at the beginning at least.

    Thus, It is necessary for us to apply from now 3 precautions which allow to make move back deafness very significantly:

• Ousting of the unilateral deaf dogs of the reproduction (thanks to BAER hearing test)

• Keeping of the reproducers which transmit patches

• Great mistrust about the lines with an important percentage of blue eyes

WHICH IS THE ORIGIN Of THE HEREDITARY DEAFNESS?

    Dalmatian, as several other races, whith white coat (English Setter, Bull-terrier, Cocker, Jack Russell…), hass a certain percentage of hereditary deafness. 

    The dalmatian 's ancestor is a uniformly pigmented dog whose pigment was erased because of a genetic mutation which was maintained by selection with excess.

   The gene (speculative) responsible for the white dress, named "invading panachure" is named sW (S = self meaning "uniform" - W = white meaning white).

    The gene sW, if it causes the absence of pigment on the coat, determines sometimes also its absence (by the combined action of another genes known as "modifying") in the cells of a portion of the inner ear called cochlea causing their degeneration during first weeks of the life, thus leading to an irremediable deafness.

Bilateral DEAFNESS and Unilateral DEAFNESS: WHICH IS THE FREQUENCY?

Unilateral DEAFNESS

    The lack of pigment can reach only one ear: it is unilateral deafness. The unilateral deafness passes, for the average observer, unperceived because the dog has a completely normal life; a very light delay with the localization of certain noises can however sometimes be noted.

Bilateral DEAFNESS

    The bilateral deaf dog  is a major handicapped dog, imposing a very constraining way of life for his wasters: lead obligatory for the walks, learning the sign language, difficult for certain exuberant dogs, possibility of aggressiveness moments, by fear.

Dominique Vincent: French Dalmatian Club veterinary surgeon

The Domain of Syrtos puppies are tested at the clinic Jeanne d'Arc in Lille.