A Guide on Deafness in Dogs
Just like us humans, dogs use their hearing as an invaluable sense. Their hearing capabilities are slightly different to ours; our hearing frequency being 20 Hz to 20,000 Hz whilst a dog’s is 40 Hz to 60,000 Hz. This means that they can hear sounds at a higher pitch, a prime example being a dog whistle; undetectable to humans but excruciatingly clear for dogs.
Dogs’ Hearing Technique
Another differing acoustic ability that canines have is the facility to change the position of their outer ear to focus upon a specific sound. By lifting and turning, the outer ear can act like a trumpet and heighten sounds. A Dog’s ear has 18 muscles that aid the titling, rotating, lowering and raising of the ear and this mobility acts like a radar helping the dog to determine where an exact sound is coming from. Add to that the fact that each ear has the ability to pick up sounds independently and you start to comprehend why a dog’s hearing is instrumental as part of its biology.
When discussing deafness in canines it is imperative to note that it can be hard to notice the signs that your dog is indeed aurally impaired. This is because they rely on smell and vibrations at lot more than we do. A dog may have been deaf for an elongated period of time before the owner even notices.
There are three types of deafness that a canine can suffer from. These are as follows:
Congenital deafness occurs as a result of the deterioration of sensory inner ear structures in either one or both ears within a few weeks of a puppy’s birth. It is a hereditary condition and studies show that if just one of the parents is deaf than the chance of the pup being deaf doubles.
Unilateral deafness is when a dog is aurally impaired or completely deaf in one ear.
Bilateral Deafness is when both of a dog’s ears experience hearing difficulties or are both completely deaf.
Apart from being born deaf due to a hereditary condition there are a few other things that may cause deafness. Ear inflammations of the middle or inner ear can contribute to permanent or temporary deafness. Infections in the middle ear can produce crud (a wax-like substance) that will stay there even after an infection has ended and block the sound transmissions that your dog would otherwise normally hear. A loud noise may also generate some form of deafness as. Another cause, although somewhat rarer, is medication. A lot of antibiotics such as gentamicin, kanamycin and neomycin can cause deafness by destroying cochlear hair cells. As a result, these drugs aren’t normally used unless it is an extremely serious illness that the dog is suffering from.
A common way for dog owners to test whether or not their dog is deaf is by hitting a saucepan, jangling keys or making some kind of sudden noise whilst the dog is not looking. The main flaw in using this technique is that it does not test for unilateral deafness. If you are worried that your dog is deaf or partially deaf then the only 100% accurate way to find out is the BAER (Brain Auditory Evoked Response) test. This is a computer-based programme that records and monitors electrical activity in the inner ear and auditory pathways in the brain.
Please be aware that this guide is for advice only and if you have concerns or worries about your pet’s hearing then please speak to your veterinarian.