Deafness in Cats

[Arch]

I'm sure I've heard that white cats can often be deaf (due to a gene unrelated to colour that happened to get bred in along with colour).  How about other cats, is deafness common?  And if they are deaf (and I don't mean in an age related way), are there degrees of deafness, as in humans?  Can a cat be completely deaf?

The reason I ask is that we've seen a cat around the recycling sight recently. It's tortie and white, and tends to skulk in and go under one of the big skips (they sit on beams, so there's a gap), and isn't keen on being approached. It was there to day as we sorted out some stuff, and was washing itself, and I noticed that when I threw a bottle into a box of bottles, making a very loud noise, it didn't flinch or anything - I did it a few more times, and made a lot of 'puss puss' noises, and it just ignored me. 

My colleague thought it looked a bit thin, and looking at it today, I thought the nose area looked a little bit raw, so we wonder if it's stray. It's not petable - I approached and offered a hand to sniff, and it walked off, although it did so with dignity rather than too hurridly.

It's rather pretty, and I hope it's not a stray. I can't take one on really, in a small upstairs flat.  But I'll keep an eye on it.

<wheedling tone>

Tiii-iiim?

 

[Clare]

Cats can be totally deaf, my brother has one called           . There's no point in naming it as it can't hear anything. It is completely white and I believe that whites are the most prone to deafness, followed by white eared cats. No idea if that has ever been proven scientifically.

Anyway is there a concerted attempt to make Tim the mad cat woman man of the forum?
 

[matthew]

My aunt used to breed cats (Norwegian Blues IIRC) but had to stop when it became apparent that whilst they were wonderfully white the tom was also carrying the deafness gene and a lot of the kittens were deaf.

[Jaded]

Alfie is deaf, but he is orange. Also he is deaf through old age, rather than genes.

Currently he is wheezing and farting and wants to be my friend.

[Kim]

As with humans, there are different kinds of deafness.

I don't think age-related hearing loss is uncommon.  I've known various elderly cats who seemed fairly oblivious to high-frequency sounds, but being cats I could never really work out whether they were actually not hearing or simply couldn't be arsed reacting.  Cats do seem pretty good at sensing vibrations, which would obfuscate matters (are they looking round because they heard you, or because the floorboards moved?).

AIUI, the gene causing deafness in white cats is correlated with blue eyes (in adults - all young kittens have blue eyes), either unilaterally or bilaterally (a cat with one blue eye will only have a hearing loss in that ear), but it's not a hard rule, because you can get white cats with blue eyes from other combinations of genes (eg. they have some Siamese in them or something).

I'm slightly disturbed that I can remember that.  I read it in a book when I was a bored teenager.  Can't remember where I left my glasses, though, can I?

[CrinklyLion]

This tortie and white cat-does it look particularly dimwitted? If so, try calling it Mogwai and see if it responds. She has a fondness for your bit of the world, and is a bit too stupid to be scared of stuff...

[Feline]

There is indeed a profound and total deafness gene linked to the gene for a white coat. The cat has to be totally white though for the gene to express itself, even a small patch of colour anywhere and they cannot be deaf for this reason. A fairly high number of white all over cats are affected. I see quite a few at work.

There are other causes of acquired deafness. There's the irreversible internal deafness of old age, middle ear disease, polyp growths in the middle ear, severe ear mite infestations or ear infections. Cats are actually notoriously hard to test the hearing of. If you do daft noisy things to get a reaction out of them they are just as likely to look at you as if you are stark raving mad and ignore the sound. A better way to do it is to get them focussed on watching one person in front of them, and then get someone else to make an attractive noise such as a mouse squeaking one from behind them. It may not work if they noticed the person behind them though, because they often ignore things they think are daft. If there is any smell associated you cannot be sure if they smelt or heard the thing, and if the noise was accompanied by a rush of air (such as clapping hands) then they can pick this up as vibration on their whiskers and can appear to have heard when they didn't. It's all a bit of a challenge for the vet who gets asked 'do you think my cat is deaf?'

[Andrij]

My aunt used to breed cats (Norwegian Blues IIRC) but had to stop when it became apparent that whilst they were wonderfully white the tom was also carrying the deafness gene and a lot of the kittens were deaf.

Those are parrots! 

[Arch]

This tortie and white cat-does it look particularly dimwitted? If so, try calling it Mogwai and see if it responds. She has a fondness for your bit of the world, and is a bit too stupid to be scared of stuff...

Ah, cheers, I'll try that. I wouldn't have said it was especially dimwitted looking, but I don't know cats well enough to judge...  I would say that it doesn't look elderly, as far as I can tell.

The compound isn't a great place for animals due to the risk of broken glass underfoot, but since we can't successfully keep small urchins out, we haven't a hope against cats!

[matthew]

My aunt used to breed cats (Norwegian Blues IIRC) but had to stop when it became apparent that whilst they were wonderfully white the tom was also carrying the deafness gene and a lot of the kittens were deaf.

Those are parrots! 

as I said IIRC, its 20 years since she stopped. 

[Kim]

Cats are actually notoriously hard to test the hearing of. If you do daft noisy things to get a reaction out of them they are just as likely to look at you as if you are stark raving mad and ignore the sound.

I assume the technology used for screening newborn babies (measuring acoustic echoes from the cochlea and electrical brain-stem response) hasn't percolated to the veterinary world, then?  I suppose there isn't much call for it, beyond reassuring Mad Cat Women and the like.  I also suspect that animals are going to be slightly less cooperative with headphones and electrodes than small babies

If barakta weren't busy cat-herding bisexuals, she could give us the deaf child's guide to cheating at distraction tests.  While humans lack the sensitivity to smells and air currents that cats have, they make up for it with intelligence, and will false-positive on distraction tests by cunning use of reflections or reading subtle changes in an adult's facial expression.  Distraction tests are notoriously unreliable, to the point where unless they're old enough to play put-the-peg-in-the-hole-when-you-hear-the-beep it's actually more useful to measure the cochlea/brain-stem response directly.  I fear how difficult it must be with a cat of even below-average stubbornness.


I remember reading about a dog with a conductive hearing loss being temporarily implanted with a BAHA, as a precursor to the implant technology being licensed for small children (the skull thickness is similar).  It looked rather silly with the processor sticking out of the top of its head, but the owners reported that it immediately started responding to its name again.  Given how long a BAHA tends to last when attached to a child, I can't imagine it would be sensible to give them to dogs (who tend to be faster and have a higher affinity for puddles) other than for ^_SCIENCE, but no doubt there are some rich Americans who'd be willing to pay for them...

[TimO]

One way to avoid a visual cue with a human, would be to use a remotely triggered device, and at a frequency which humans can't hear, so any humans in the room couldn't react to it, and give the cat a hint (cat's hearing goes to much higher frequencies than humans, as far as I recall).

Of course, I'm guessing that with old age, cats high frequency hearing becomes impaired first, as with humans, so it wouldn’t work so well with age related hearing loss.

[Feline]

There is currently one specialist unit, the Animal Health Trust in Newmarket, that I have the option of referring my patients to for a proper diagnosis of deafness. It's really only an option for the very wealthy, I don't think the pet insurance companies would cover a clinical work-up of deafness (although to be fair I have never tried to put through a claim for this for anyone). http://www.aht.org.uk/sa_neurology.html

[rogerzilla]

I find that pouring Go-Cat into a metal food bowl is a good test of whether cats can hear.

[TimO]

My fridge door was a pretty good test of Talisker.  No matter how quietly you'd open it, he'd be there a few seconds later, looking optimistic.  Of course, cats may just have yet another sense which is used by their Hamdar.

[TimO]

Anyway is there a concerted attempt to make Tim the mad cat woman man of the forum?

I'm all kittened and catted out, there's no more room at the inn!

(... and these two are going to cost £15 a day or so to put in a cattery occasionally, which is enough).

[Gattopardo]

No offers to cat annoy from your local forumites?

[barakta]

I didn't really do the fudging hearing tests, didn't see the point.  I wanted accurate audiometry or they'd have given me even shitter hearing aids.  Already had people claiming I was less deaf than I am cos I speak ok *eyeroll*.

Although I did used to turn to face parents when they came into my bedroom as a pre-deaf-diagnosed baby cos I could see them in the mirror which had been stored behind my cot

[Arch]

I didn't really do the fudging hearing tests, didn't see the point.  I wanted accurate audiometry or they'd have given me even shitter hearing aids.  Already had people claiming I was less deaf than I am cos I speak ok *eyeroll*.

Although I did used to turn to face parents when they came into my bedroom as a pre-deaf-diagnosed baby cos I could see them in the mirror which had been stored behind my cot

Impressive that you worked the mirror out so early - amazing what humans will do to compensate.

My Mum had her first eye test at school aged 5. They got her to cover one eye and read the letters, and then said to cover the other eye, and she said "Oh that won't work!" 

"Why not?"

"Well, I can't see out of that one!"

She'd always assumed that was the way it was - you had one eye for seeing, and one to balance it out on your face.

Cue glasses to correct a nearly blind right eye...