Otitis Externa- how to treat when tympanic membrane not visible?

RE: Otitis Externa- how to treat when tympanic membrane not visible?

Emily Ross — Wed, 20 Jan 2021 21:30:17 GMT

What are everyone's thoughts on controlling humidity in the ear canal? I have seen a few ears which have been treated with instilling cleaner in the canal several times a day for over a month without drying which have then become painful and the skin appears somewhat macerated. Any tips on application advice to clients?

Another reminder of what water can do came in to see me today. The owner had been cleaning his dogs ears with water and on presentation 6 weeks ago the dog was incredibly painful in both ears with purulent discharge. He didn't go away with topical treatment while awaiting C&S (I forget the organism), didn't pick any meds up, and the client only brought the dog in finally today having stopped using water. The ears were comfortable, no concerns on otoscopy, and negative on cytology

RE: Otitis Externa- how to treat when tympanic membrane not visible?

Emily Ross — Wed, 20 Jan 2021 21:20:41 GMT

Thanks David, there's some brilliant advice here to put in practice

RE: Otitis Externa- how to treat when tympanic membrane not visible?

Joyce Whitehead — Mon, 18 Jan 2021 21:05:41 GMT

Great video!

RE: Otitis Externa- how to treat when tympanic membrane not visible?

Sarah Keir — Mon, 18 Jan 2021 20:41:33 GMT

[quote userid="17458" url="~/001/veterinary-clinical/small-animal/dermatology/f/discussions/29607/otitis-externa--how-to-treat-when-tympanic-membrane-not-visible"]suggest TM rupture is rare even with OE[/quote]

I had in my head that TM rupture is common and that it is very difficult to assess!

RE: Otitis Externa- how to treat when tympanic membrane not visible?

David Bentley — Mon, 18 Jan 2021 17:23:29 GMT

I've seen enough dogs with ruptured TMs (including recently a Cockerpoo with bilateral Cholesteatomas which looked initially just like your typical atopic dog with ceruminous otitis) that I would always be very wary of using any prescription ear drop (or even ear cleaner containing propylene glycol or acids/carbamide peroxide) without knowing the TM is intact.

Although rare, I've seen dogs go down with vestibular signs or deafness after using prescription drops when the state of the eardrum was not known with certainty and it was discovered that the TM was indeed ruptured.

If you have a stenosed ear canal, use systemic steroids (pred 1-2mg/kg sid) to open it up and treat the bugs based on cytology, so if Malassazia use either systemic Itraconazole or Canestan solution topically ( clotrimazole is safe if ruptured TM). If bacterial infection then you can use Triz aural /Before X/TrisNAC with added Baytril or gentamicin eg 16ml Baytril injectable in 100ml Tris or 4x 80mg vials Gentamicin in 100ml Tris. Despite fears of Gentamicin ototoxicity, Sue Patterson published some work a few years ago showing that based on BAER testing, Gentamicin at this concentration is not ototoxic.

It's not just the risk of Ototoxicity. I recently saw a dog that had been treated for a grass seed rupturing a TM and was then given Otoclean ( 70% propylene glycol) as an ear cleaner afterwards(!!) 8 weeks later, with worsening vestibular signs, I saw the dog and the TM had healed apart from one tiny slit. Pressure on the TM then forced a large amount of Otoclean out from inside the middle ear! I don't like the idea of the oily vehicle on ear drops getting into the middle ear. Even if it is not directly ototoxic, it's going to remain in the middle ear for a long time. See this video Otoclean starts coming out from behind eardrum at 1.30.

vimeo.com/.../d5366182d8