Client care for infected cat and dog ears depends on using medications properly, and practitioners differ on best use of ear cleansers.
“I recommend that pet owners clean the ears commensurate with the quantity of exudates that are produced during the course of treatment,” said Jon Plant, DVM, owner of SkinVet Clinic in Lake Oswego, Ore.
“Some ear cleansers, like those containing tris-EDTA, are designed to use as a pre-treatment flush 15 minutes prior to applying the topical medication, regardless of the amount of exudate that is present,” he said. “Other cleansers are acidifying, and the application of some ear medications should be delayed so that the pH returns to normal.”
Not only do acidic cleansers lessen the effectiveness of aminoglycoside (gentamicin, neomycin) and flouroquinolone (enrofloxacin, orbifloxacin) antibiotics, they sting the animal’s ears, noted Paul B. Bloom, DVM, Dipl. ACVD, Dipl. ABVP, owner of the Allergy, Skin and Ear Clinic for Pets in Livonia, Mich.
“Exceptions include tris-EDTA-based products (by Dechra, Sogeval and others) and Epi-Otic Advanced (by Virbac),” Dr. Bloom said.
Tris-EDTA is short for tromethamine and edetate disodium dihydrate. Dechra Veterinary Products contain a trademarked medical-grade formula that is a cut above commercial grade, according to Dena Ware, companion animal marketing manager. Tris-EDTA breaks down pathogen cell walls, potentiating the effects of such active ingredients as ketoconazole, she said.
Bloom prefers his clients to leave the cleaning to him.
“I flush the ears with an ear cleaner followed by a bulb-syringe flush at the clinic, then send the client home with an ointment,” he said. “Ointments contain paraffin, petroleum jelly, mineral oil or propylene glycol, which tend to dissolve cerumen, so these medications are basically cleaning the ear itself. On recheck, you should see a lot of ear medicine in the canal, but not debris, if they are medicating it properly.”
Cristiano von Simson, DVM, veterinary technical services director for Bayer Healthcare LLC Animal Health of Shawnee, Kan., said the extent of cleaning necessary depends upon type of ear infection and secretions produced.
“You don’t want a lot of poking and repeated cleaning of sore ears, but if it’s a chronic, nasty infection, the ears might need to be cleaned a second time during treatment,” von Simson said.
When veterinarians ask owners to clean their dog or cat's ears at home, “You should be having them flood the ear. This means that a bottle of cleaner may last three or four treatments,” Bloom said. “So that means owners should be buying four to five bottles of ear cleanser a year.” Bloom said when he lectures to veterinarians, he asks for a show of hands if they have clients buying ear cleanser in that amount.
“Nobody raises their hand. Clients rarely follow through,” he continued. “In fact, they tend to use it when the ears are flaring up—which is the time the cleaner is most likely to hurt! So I don’t recommend using cleaners at home, at all.”
Plucking hair from the ear canals is another practice eschewed by Bloom.
“It’s only necessary if the ears are infected,” he said. “For those who do pluck ears, how often? Show me the science that supports that.”
A final note concerns ear cleaning in cats, which many believe is best done gently by a trained professional.
“My impression is that a lot of the cats I’ve seen for head tilts over the years have been those that a well-meaning technician decided to clean their relatively normal ears while they were under anesthesia for some other procedure, only to have them wake up with a head tilt,” said Plant, a former dermatology professor at Oregon State University’s College of Veterinary Medicine. He blogs about this and related topics at /redirect.aspx?location=http://skinvet.wordpress.com/.
“Do not use products that contain chlorhexadene in cats,” added Bloom. “You need to be very careful about what you put into the ears and how you flush them. It’s possible to cause transient or permanent vestibular syndrome.”