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67 MAY/JUNE 2017 ■ TVPJOURNAL.COM DERMATOLOGY DETAILS drainage and ventilation. Most ear products contain various combinations of glucocorticoids, antibiotics, antifungals, and parasiticides. • Otic products containing betamethasone (Otomax) and dexamethasone (Tresaderm) are usually effective but can be absorbed systemically and cause adrenal suppression with long-term use, so they should be used cautiously. In one study, a more potent yet "soft" glucocorticoid, mometasone (Mometamax), showed no adrenal suppression after 1 week of therapy. 12 In cases of allergic otitis externa, long-term topical glucocorticoids may be required with careful monitoring for adrenal suppression or local side effects, such as pinnae hair loss. Products with weaker- strength glucocorticoids should be used in these situations, such as those containing 1.0% or 0.5% hydrocortisone (Zymox HC, zymox.com ). I often recommend fluocinolone and dimethyl sulfoxide (Synotic, zoetisus.com ), with great results for many chronic, hyperplastic, and stenotic otitis cases. New Food and Drug Administration– Approved Single-Dose Antimicrobial and Steroid Otic Solutions Two new veterinarian-administered products containing florfenicol, terbinafine, and mometasone furoate (Claro, bayerdvm.com ) and florfenicol, terbinafine, and betamethasone acetate (Osurnia, osurnia.com ) are indicated as single-dose treatments for canine otitis externa associated with susceptible strains of yeast (Malassezia pachydermatis) and bacteria (S pseudintermedius). The duration of effect is 30 days for Claro and 7 days for Osurnia. Ears should not be cleaned at home after application. The recommendation is for use in the clinic after ear cleaning, and only with intact tympanic membranes. These are great options for patients that do not allow topical therapy at home and to improve compliance, with potential benefit for acute or mild otitis cases. Their use in chronic severe otitis cases is limited because severe hyperplasia and stenosis preclude ear cleaning and evaluation of the tympanic membrane. Systemic Therapy Indications for systemic therapy include the following: • Otitis externa that is severe and unresponsive to topical therapy alone • Concurrent otitis media • Owner unable to medicate with topical therapy • Topical therapy precluded by adverse reactions • Marked proliferative chronic changes Antibiotics These drugs may be used in animals with otitis media, moderate or marked proliferative changes with suspected otitis media, or no response to appropriate topical therapy and cleansing. I usually recommend C/S before a systemic antibiotic is selected. Usually, higher doses are recommended to achieve good penetration in the middle ear. Treatment duration may vary; however, I usually treat for 1 month after resolution of clinical signs and healing of the tympanic membrane (from spontaneous perforation or myringotomy). Fluoroquinolones may be prescribed when Pseudomonas species, other relevant gram-negative organisms, or very resistant gram-positive bacteria are isolated and susceptibility is confirmed after culture. Higher doses than usually recommended may be needed. Oral fluoroquinolones that may be used include enrofloxacin (Baytril) at 10 to 20 mg/kg q24h, marbofloxacin (Zeniquin, zoetisus.com ) at 5 to 10 mg/kg q24h, or orbifloxacin (Orbax, merck-animal-health-usa.com ) at 10 mg/kg q24h. Ciprofloxacin should be avoided in dogs because oral absorption is inconsistent and low (58.4%) with oral tablets, 15 potentially leading to inefficacy and bacterial resistance. In rare cases, injectable antimicrobials, such as aminoglycosides, carbapenems, and ceftazidime sodium, may be required to treat multidrug-resistant otitis cases. Potential side effects with these therapies need to be considered. Referral of these cases to a dermatologist should be considered, particularly when treatment options are limited.