An animal can be born deaf (congenital deafness) or it could acquire the deafness during the course of its life. For an animal to be considered totally deaf, the problem must greatly affect hearing in both ears.

 

Congenital deafness

(= inherited deafness)

Certain breeds predispose to deafness. The incidence of deafness among Dalmatians (and any dog with predominant white coats, it seems) is relatively high. Dalmatians (you remember them from the Walt Disney movie) are a weird breed anyway. For example, no other breed of dog excretes uric acid of the human type, therefore it is the only breed that can form uric acid stones in the bladder. Anyway, that was just an aside, a point which might be of interest to those very erudite of you who read these articles. Actually, I suppose I am addressing only the Oditt family who has until recently had the experience of caring for a pure bred Dalmatian.

so140112steveOf course, other breeds like the Bull Terrier (again, especially the white ones), the Scottish Terrier, the Old English Sheepdog, Boxers, the Border Collie, the English Setter, and the Fox Terrier have been known to be afflicted with deafness more than other breeds.

The fact of the matter is that all mammalian species and breeds can give birth to deaf offspring. Interestingly enough, because of breeding techniques and selection measurers used by knowledgeable animal breeders, deafness in the predisposed breeds is becoming less and less of a problem. For example, that favourite of children, the Cocker Spaniel, seems now to be free of the defect which must have been eliminated through specific breeding practices.

In passing, I should mention that cats with blue eyes and white fur are more prone to congenital deafness than cats with other colourations.

 

Acquired deafness

Any condition, the sequel of which will block up both external ear canals, will result in some degree of deafness. The level of the deafness will coincide with the magnitude of the blockage. For example, ear infections, like the ones we described last week and the week before (chronic otitis externa and media), could lead to the total sealing up of the ear canals and the destruction of the middle ear, consequently deafness.

 

Other causes of acquired deafness could be:

 

  • Mechanical trauma – eg a blow to the temporal bone

 

  • Potentially toxic drugs (and poisons) – eg pro longed medication with Gentamicin, Neomycin,                 Streptomycin, etc. Even salicylates (the salt

produced by salicylic acid (aspirin) has been                        linked to deafness in the dog.

 

  • Cancers (neoplasms) of the ear or in the brain

 

  • Old age. Senility deafness (dogs over 10 years of age) is insidious. It creeps up unnoticed. In fact,                 deafness is only noticed in the canine senior

citizen when the latter becomes blind as well.

 

  • Accumulation of wax and debris

 

  • Aftermath of diseases, eg canine distemper

How do we suspect deafness?

The determination of deafness in puppies and young dogs is always a difficult task. They are hyper, and, as all young children, they don’t listen anyway. As they grow older and can respond to an auditory stimulus, the deafness exhibits itself more clearly. Some of the signs are:

(i)   Failure to respond to calls and commands

(ii) Failure to respond to a noise that the other animals have reacted to. For example, the deaf dog will remain sleeping, while the others are running around barking their heads off at something or somebody that has excited them.

(iii) Excessive barking

(iv) Voice change

(v)   Confusion on the face of the animal when a command is given

(vi) The non-movement of the ear flaps (pinnae) when a command is given

Treatment

As always, once the cause has been removed (acquired deafness), the animal’s hearing will be restored. So, for example, if the ear canal was blocked up because of a chronic infection, then killing the germs, removing the swelling and the inflammatory condition should help immensely. Similarly, the surgical opening up of the canal that has been blocked could solve the problem.

 

There is really no cure for congenital deafness. In this case, since the problem is genetically anchored, one would need to breed away from this disadvantageous gene. In effect, this means ensuring that dogs which are born deaf do not produce offspring.

 

Have pleasant week!

 

Please implement disease preventative measures (vaccinations, routine dewormings, monthly anti-Heartworm medication, etc) and adopt-a-pet from the GSPCA’s Animal Clinic and Shelter at Robb Street and Orange Walk, if you have the wherewithal to care well for the animals. Do not stray your unwanted pets, take them to the GSPCA’s Clinic and Shelter instead. We still have the free spay and neutering programme. Exploit it. If you see anyone being cruel to an animal, or if you need any technical information, please get in touch with the Clinic and Shelter by calling 226-4237.

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