Expert: Dr. Louis N. Gotthelf - 12/5/2010

Question
my older dog went deaf after using mometamax.  is this reversible?  how?

Answer
Mometamax contains a very toxic antibiotic called gentamycin.  That is most likely what is causing the problem.  You need to let your vet know about this so that they can switch to a different type of antibiotic to treat the infection.  In most cases of gentamycin ototoxicity, if you stop the medicine, the hearing will return within 2-3 weeks.  The gentamycin has to diffuse out of the cochlear nerves in the inner ear and that can take a while.