Ear Infection (Otitis Externa)

Ear Infection (Otitis Externa)

Species: Dog

Breeds Affected: All Breeds (dogs with floppy ears or allergic skin disease are predisposed – e.g. Basset Hounds, Cocker Spaniels)

Otitis externa is an infection/inflammation of the external ear canal. It’s commonly caused by an overgrowth of bacteria or yeast, often secondary to factors like moisture (e.g. after swimming), allergies, ear mites in puppies, or excessive wax. Up to 20% of dogs experience ear infections, and recurrence is common if underlying causes (allergies, etc.) are not addressed.

• Typical signs are the dog shaking the head or scratching the affected ear frequently. The ear canal may be red
• swollen
• and have a foul odor. Often there is discharge: it can be brown/black and waxy (common with yeast or mites) or yellowish pus (with bacterial infections). The ear may be painful – dogs may yelp when the ear is touched or tilt the head to one side. In chronic cases
• the ear canal skin may thicken and the opening can narrow. If the infection spreads to the middle/inner ear
• signs like imbalance
• walking in circles
• or hearing loss can occur.

Treatment involves thoroughly cleaning the ear canal and using appropriate medication to eliminate the infection. The veterinarian will examine and often swab the ear to determine if it’s bacterial or yeast (or both). A deep ear cleaning (often under sedation for severe cases) is performed to remove debris. Then a course of topical ear drops is prescribed, containing some combination of an antibiotic (for bacteria), antifungal (for yeast), and anti-inflammatory (steroid) to reduce swelling and itch. In severe or resistant cases, systemic treatments may be added: oral antibiotics or antifungals, and possibly oral steroids to reduce canal swelling. Underlying causes (like allergies) are addressed to prevent recurrence.

Topical ear medications are key. Common products include combos such as otomax, surolan, or claro, which typically contain an antibiotic (e.g. gentamicin, neomycin), an antifungal (e.g. miconazole, clotrimazole) and a corticosteroid (e.g. betamethasone) for inflammation. These are applied into the ear canal daily. If the ear is very swollen, a vet may first give an oral prednisone course for a few days to open the canal for better drop penetration. For severe bacterial infections, an oral antibiotic (like enrofloxacin or cefpodoxime) may be prescribed in addition to drops. Pain can be managed with NSAIDs if needed. Keeping the ear clean and dry is part of treatment – a drying ear cleaner or ear cleaning solution may be recommended for routine use once the acute infection is controlled.