Otomax and deafness (or just deafness!)

Re: Otomax and deafness (or just deafness!)

sophia guymer — Fri, 26 Nov 2010 15:02:43 GMT

[quote user="Martin Atkinson"]On a side note though; ear plucking is not advised these days as it can damage the wall of the ear canal and leave it more inflammed and prone to further infection,[/quote]

OOOOh, that might be why recently all the dogs that used to have their ears plucked nicely at the groomers, now come in with clogged up ears! Hmmm, so far I have told owners to point it out to the groomer and ask for plucking next time. A couple we have done in house as the ears were starting to be a problem. Plucked them, problem gone!

I had one in not so long ago, as a behavioural patient. Was starting to be aggressive, used to be such a lovely dog. Now biting when o tried to get stuff off him he shouldn't eat. After intensive conversation turned out to only be if o approached dog from behind, low and behold, the dog could hear but his hearing must have been impaired: Ears totally clogged up with matted hair. Removed, cleaned ears, happy dog and owner. No more biting!

Dogs shouldn't be bred with hair in ears!

Re: Otomax and deafness (or just deafness!)

sophia guymer — Fri, 26 Nov 2010 14:56:00 GMT

years ago my terrier (rip) needed topical treatment for an ear infection 2x on different occasions.

The first time used canaural, completely deaf while on treatment! Seriously, competely and utterly deaf. Few days after treatment stopped his hearing returned.

Ditto the next time when we used otomax. I put it down to the product actualy being in the ear, like water in your ears, but then again, he really couldn't hear anything at all. Came right again both times though.

Re: Otomax and deafness (or just deafness!)

Gerry Henry — Tue, 23 Nov 2010 09:10:22 GMT

Thanks all for the input; the hibiscrub is so dilute could it really be the cause? Prob no more than 5mls in 400mls lukewarm water; is this enough to cause problems? Thanks again for the considered replies, being single handed gets a bit lonely sometimes *sniff*

Re: Otomax and deafness (or just deafness!)

Evelyn Barbour-Hill — Tue, 23 Nov 2010 00:32:41 GMT

Sorry, but chlorhexidine can be ototoxic even across an apparently intact tympanic membrane. I had that happen once, 31 years ago.

Re: Otomax and deafness (or just deafness!)

Anthony Todd — Mon, 22 Nov 2010 23:14:07 GMT

[quote user="Anthony Todd"]Pretty sure that chlorhexidine is documented[/quote]

Yes, sorry but loads of references and it's in Slatter. Google "chlorhexidine + deafness"

Re: Otomax and deafness (or just deafness!)

Anthony Todd — Mon, 22 Nov 2010 23:10:54 GMT

[quote user="Alex Allen"] very unlikely that either the chlorhexidine[/quote]

Pretty sure that chlorhexidine is documented in humans as causing profound deafness; think it was in Finland.

Certainly we had an alsation with total deafness after chlorhexidine wash.

Re: Otomax and deafness (or just deafness!)

Alex Allen — Mon, 22 Nov 2010 18:06:33 GMT

For your defence it is very unlikely that either the chlorhexidine, alcohols, detergents or gentamicin could have permeated into the inner ear structures if the tymp memb was intact. Of all the compounds my fear would be the dilute hibi that might be responsible. Personally I prefer lots of saline as a flush given the potential for adverse reactions. Also be careful with the choice of ear flush solutions as they may interfere with antibiotic function.

A study in healthy dogs (Strain et al 1995) showed that gentamicin was not ototoxic when instilled into the tympanic bulla for 3wks - this is quite different to the parenteral administration of aminoglycosides where nephrotoxicity is a serious concern followed by ototoxicity - which is either vestibulotoxicity or cocleotoxicity. Gentamicin is actually more likely to cause vestibulotoxicity than cochleotoxicity. Also deafness after systemic use of aminoglycosides takes time to manifest - typically the endolymph gradually accumulates the drug and eventually enough of the crucial cells are destroyed producing the deafness. Many drug induced ototoxicities are permanent so any improvement rules out drug causes.

As a word of caution if the tymp memb is ruptured any treatment is off label and a consent form is wise in case of problems.....

To get such an acute onset deafness would be more likely otitis media and/or clogging up of the ear canal. If the owner is willing then a radiograph or two might reveal evidence in the tymp bulla. Myringotomy + culture sens + flushing would be next but vestibular syndrome is a risk the owner needs to be warned about.

Doing a procedure 200 times a year just means statistically your more likely to have nightmare case

Remember to report any SAR to the drug companies

Re: Otomax and deafness (or just deafness!)

Mark Holmes — Mon, 22 Nov 2010 16:59:35 GMT

Was the dog sedated? We had a cat who woke up from sedation apparantly deaf. I cannot tell you the outcome she has dropped off the radar and I cannot remember the name.

Re: Otomax and deafness (or just deafness!)

Gerry Henry — Mon, 22 Nov 2010 16:49:22 GMT

Har Har, I like a man with a sense of humour. No, its hearing was fine beforehand, likewise the eardrums; GA again today, ears looked fine, spotless and hairless! Re plucking, well if the hair has felted and is blocking the ext opening in a great plug I don't see we have much of a choice.

It really is most perplexing Martin but thanks for the input.

Re: Otomax and deafness (or just deafness!)

Martin Atkinson — Mon, 22 Nov 2010 15:16:14 GMT

Are you sure if wasn't deaf before you started? Or that there isn't a dollup of wax or some fluid still down there? Not sure I'd use HIbiscrub but in theory if the tympanic membranes were intact it shouldn't have caused the problem. On a side note though; ear plucking is not advised these days as it can damage the wall of the ear canal and leave it more inflammed and prone to further infection, best just to use regular ear cleaning drops to stop it getting clogged up and leave the hair there. As for the last question: check your VDS insurance is up to date