Osurnia in Dogs

Osurnia is a prescription ear gel used in dogs for certain cases of otitis externa, which is inflammation and infection of the outer ear canal. It contains three active ingredients: florfenicol, an antibacterial; terbinafine, an antifungal; and betamethasone acetate, a steroid that helps reduce swelling, redness, pain, and discharge. The FDA-approved label states it is indicated for otitis externa in dogs associated with susceptible strains of Staphylococcus pseudintermedius and Malassezia pachydermatis. It is a veterinary medication, not an over-the-counter ear product, and it should be used only under your vet’s direction.

Osurnia is designed to stay in the ear canal after application rather than running back out like some liquid drops. Your vet places one full tube into each affected ear, then repeats the treatment 7 days later. The gel is meant to remain in contact with the ear canal, which is why the label says not to clean the ear canal for 45 days after the first dose unless your vet changes the plan. That long contact time can be helpful for pet parents who have trouble giving daily ear medication at home.

Each ingredient has a different role. Florfenicol targets susceptible bacteria, terbinafine targets yeast, and betamethasone acetate helps calm inflammation. That combination can be useful when cytology shows a mixed infection with bacteria and yeast plus a painful, inflamed ear canal. Even so, Osurnia is not the right fit for every ear problem. Ear infections often have an underlying cause, such as allergies, moisture, ear conformation, or chronic skin disease, so your vet may also recommend follow-up care to reduce recurrence.

Most dogs tolerate Osurnia well, but side effects can happen. In the U.S. field study listed on the label, reported reactions included elevated alkaline phosphatase, vomiting, increased liver enzymes, weight loss, and hearing decrease or loss. Because the product contains a steroid, the label also warns that topical otic corticosteroids have been associated with adrenocortical suppression and iatrogenic hyperadrenocorticism in dogs. Your vet may be more cautious in dogs with liver disease or dogs already receiving other steroid medications.

There are also important local safety concerns. Osurnia should not be used in dogs with a known perforated eardrum, and the integrity of the tympanic membrane should be confirmed before treatment. If hearing loss, head tilt, balance changes, or other vestibular signs appear during treatment, the dog should be rechecked promptly. Eye exposure is another known risk. FDA safety communications note that Osurnia can cause irritation or injury if splattered into human or animal eyes, so veterinary staff are advised to wear eye protection and restrain dogs during administration.

Osurnia is a clinic-administered medication. The labeled regimen is one tube per affected ear, followed by a second dose 7 days later. Before the first dose, your vet should clean and dry the external ear canal. After the gel is placed, the base of the ear is gently massaged so the medication reaches the lower ear canal. Because the medication is intended to remain in place, the label says not to clean the ear canal for 45 days after the initial administration.

Pet parents should not try to improvise the schedule or add other ear products unless your vet says to do so. If the ear is still painful, draining heavily, or not improving, your vet may want to recheck cytology, look for resistant bacteria, or investigate deeper disease such as otitis media. Cornell notes that debris can block medication from reaching the infection, while Merck emphasizes that treatment choices should be guided by cytology and the condition of the ear canal. In other words, Osurnia can be convenient, but it still works best when the diagnosis and ear prep are appropriate.

Published interaction data for Osurnia are limited, but caution is still important. Because it contains betamethasone acetate, your vet may review whether your dog is also receiving oral, injectable, topical, or inhaled steroids. Combining multiple steroid exposures can increase the chance of systemic steroid effects in some dogs. The label also advises caution in dogs with impaired hepatic function, and PetMD notes that all medications, supplements, and medical conditions should be discussed before treatment.

Osurnia also may not be the best choice when another ear medication is already in place, when the ear needs repeated cleaning, or when the eardrum cannot be confirmed intact. Merck notes that topical ear products should be selected based on cytology or culture and that some products can irritate inflamed ears or pose ototoxic risk if the tympanic membrane is not intact. If your dog is on other medications or has chronic, recurrent ear disease, ask your vet whether Osurnia fits the current ear findings or whether another option would match the situation better.