Expert: Dr. Louis N. Gotthelf - 2/14/2011

Question
My 10 yr old Westie was diagnosed with an ear infection (yeast) about 2 weeks ago.  Our vet prescribed Mometamax (8 drops per ear for 30 days) and Ketoconazole.  I've noticed in the past 4-5 days that she is not responding to sounds/noises where she normally would be quick to react.  After researching her medications, I now see that Mometamax may cause hearing loss in older dogs.  I spoke with our vet today and she said she was not aware of either drug causing hearing problems, and my dog's issue was either a buildup of medication, the infection or (coincidentally) age causing the hearing loss.  This seems to be too much of a coincidence for it to be caused by age.  We still have nearly 2 weeks to go on the treatment.  Should I discontinue use of the Mometamax?  Any advice would be appreciated.

Answer
The medication in mometamax is called Gentamycin.  It can be toxic to the inner ear and it can cause deafness.  This has been well documented. Withdrawing the gentamycin usually causes the hearing to return in about 2 weeks.  Ask your vet if there is an alternative drug that you can use to get away from the gentamycin.  For a yeast infection, an antibiotic is really not needed at all.  The ketoconazole, if it is in tablet form, does not get into the ears in enough quantity to do much.  There is a good topical ketoconazole product called Malacetic Ultra Otic made by DECHRA that works very nicely in these yeasty ears..