If your dog keeps shaking his head, pawing at one ear, or the house suddenly smells faintly sour near his ears, you are almost certainly dealing with otitis externa, an inflammation of the outer ear canal. The itching and odor come from yeast or bacteria that normally live quietly in the ear but multiply once something irritates the canal skin, whether that's trapped water, an allergy flare, a lopsided ear shape, a grass seed, or (mostly in cats) ear mites. The good news: caught early, most of these infections clear up quickly with the right diagnosis and a full course of treatment. Left alone, they get harder and more painful to treat with every passing week.
Washington Family Vet Clinic is a veterinary clinic in St. George that diagnoses and treats ear infections in dogs and cats, and it's one of the most frequent reasons pets come through our doors. Here's what's actually going on inside that ear, why it happens, and what to do about it.
What's Happening Inside a Dog's or Cat's Ear
Dog and cat ear canals bend sharply, almost like an L, dropping down the side of the skull before turning inward toward the eardrum. That bend is great for shielding the eardrum but terrible for drainage. Wax, water, and debris pool in the horizontal section and just sit there.
Under normal conditions, healthy skin lining that canal keeps resident microbes in check. Inflame that skin, and the canal turns warmer, damper, and more inviting, giving yeast and bacteria the opening they need to take over. That's the swelling, gunk, and smell you're noticing. If it goes unchecked long enough, infection can push through the eardrum into the middle ear (otitis media), a much more painful problem that can throw off balance and hearing.
The Usual Suspects Behind Recurring Infections
Trapped Water
Any moisture left behind after a bath, a swim, or a grooming session softens the canal skin and builds the humid conditions yeast thrives in. Dogs who love the water, or get bathed often without a thorough ear dry-off afterward, tend to be repeat visitors to the exam room.
Allergies Nobody Talks About
Here's a fact most pet owners never hear until their third or fourth ear infection: allergies (to pollen, dust mites, mold, or certain food ingredients) are the top underlying cause of repeat ear infections in dogs. Allergic skin disease affects skin everywhere, and the ear canal is lined with skin, too. In some dogs, the ears are the only place the allergy ever surfaces. If your dog has had multiple infections this year, the real fix isn't a new bottle of drops, it's figuring out what's driving the allergy in the first place.
Floppy Ears and Narrow Canals
Breeds with heavy, drooping ears (think spaniels, retrievers, hounds) trap heat and moisture more easily, which shows up clearly in our St. George exam rooms. Excess hair inside the canal or a naturally narrow canal creates the same airflow problem. Ear shape alone won't cause an infection, but it lowers the threshold for everything else on this list.
Ear Mites
These microscopic parasites live inside the canal, feed on skin debris and wax, and cause relentless itching. A telltale sign is dark, crumbly discharge that looks a lot like used coffee grounds. Mites show up most often in kittens, young cats, and shelter pets, and they spread fast between housemates, so if one pet tests positive, the others need a look too.
Grass Seeds and Foreign Debris
Awns and seed heads can work their way into the canal, irritate the lining, and trigger a sudden, one-sided infection. A classic tipoff is a dog who was romping through tall grass or brush and comes home shaking his head hard on one side only. This calls for a veterinarian to remove the debris promptly, not a home fix.
Signs You Shouldn't Ignore
Head shaking or a head tilt to one side
Scratching, pawing, or rubbing the ear against furniture or carpet
A yeasty, sour, or musty odor
Brown, yellow, black, or waxy discharge
Redness or swelling on the ear flap or at the canal opening
Flinching, yelping, or pulling away when the ear is touched
Sudden reluctance to be petted on the head
Aggressive head shaking can burst a blood vessel inside the ear flap, causing it to balloon up (called an aural hematoma), which is its own veterinary emergency.
Cats Show It Differently Than Dogs
Ear infections are much less common in cats than dogs, and the causes shift too. Ear mites are the leading culprit in kittens and young cats. If an adult cat develops a one-sided infection with no mites present, that warrants a deeper look, since polyps or tumors can sometimes block drainage and drive infection from within.
Cats also hide discomfort well. Instead of dramatic head shaking, watch for a flattened ear, a bald or scruffy patch near the ear from overgrooming, or a cat who suddenly won't tolerate having her head touched.
What to Expect During the Exam
Your veterinarian starts with an otoscope, a lighted cone that lets us see the full canal for swelling, debris, foreign material, growths, and the eardrum's condition. Knowing whether the eardrum is intact matters, because certain medications are unsafe to use if it's ruptured. Mites are usually spotted right here, either moving under the light or on a swab mixed with a drop of mineral oil.
Next comes cytology: a swab of the discharge gets stained and checked under a microscope in the clinic, right then and there. Within minutes we can tell whether yeast, bacteria, or a combination is behind the flare-up, which matters because each organism responds to a different medication.
Some ears are simply too swollen or painful to check thoroughly while your pet is awake. In those cases, sedation isn't an extra step, it's what allows a proper exam and cleaning without turning ear care into a stressful wrestling match your pet will remember next time.
Treating the Infection the Right Way
Treatment starts with a professional ear cleaning so medication can actually reach the canal wall instead of sitting on top of debris. From there, your veterinarian prescribes medication matched to the exam and cytology findings, typically drops or ointment for home use, sometimes a longer-acting product applied in the clinic. Mites require an antiparasitic treatment, and other pets in the household usually need checking and treating as well. If allergies are the root cause, managing that allergy becomes part of the long-term plan.
The specific product and treatment length depend entirely on what's growing in your pet's ear, so that decision belongs with your veterinarian. Two rules apply no matter what: finish every dose of the prescribed course, and come back for the recheck so we can confirm the ear is actually clear, not just quieter.
Skip the Vinegar Rinse: Why DIY Treatment Backfires
Search the internet and you'll find plenty of suggestions for vinegar rinses, hydrogen peroxide, or rubbing alcohol. On already-inflamed canal skin, these sting badly, dry out unhealthy tissue further, and often make things worse. If the eardrum happens to be ruptured, pouring liquid into the ear can reach the middle ear and cause lasting harm, including hearing loss. Reaching for leftover medication from a past infection is another common misstep, since the current infection may involve a completely different organism, meaning the wrong product only half-treats it while helping resistant bacteria take hold.
Quitting treatment early is probably the single most common mistake pet owners make. Pets often look and act much better within a few days, so the drops stop. Underneath, though, the organisms are knocked back but not gone, and the infection returns, frequently worse than before. Repeated half-treated infections thicken and scar the canal lining over time. In severe, chronic cases the canal can narrow so much that medication can't reach the infection at all, and surgery becomes the only remaining option.
Ear Health Habits for St. George Pets
Utah's dry climate and hot summers create their own version of the ear-infection risk that pet owners elsewhere don't always deal with. Dogs cooling off in canals, lakes, or backyard pools around the region still trap moisture in their ears just like anywhere else, and the sharp swing from hot days into cooler desert nights can stress skin and immune function, which can aggravate underlying allergies. A few habits go a long way toward preventing trouble:
Dry the ears within 48 hours of any swim or bath. Blot the visible part gently with a cotton ball or soft cloth, and ask us whether a drying ear cleaner makes sense for your dog.
Check ears weekly. Lift the flap, look for redness or discharge, and give it a quick sniff; a healthy ear barely smells at all.
Treat repeat infections as an allergy signal, not just an ear problem. Managing the underlying allergy is usually the only way chronic ear cases actually resolve.
Clean only as directed. Over-cleaning a healthy ear irritates the canal and can start the very infection you're trying to avoid.
Never insert cotton swabs into the canal. They pack debris deeper toward the eardrum and can cause injury.
Stay current on parasite prevention. Many routine flea products also guard against ear mites, which matters for pets that spend time outdoors around St. George parks and trails.
When It's More Than an Ear Infection
Any ear symptom lasting more than a day, or obvious pain, discharge, or odor, deserves a veterinary appointment. These infections are genuinely uncomfortable, and waiting rarely helps.
Treat the following as urgent: a head tilt that won't straighten, stumbling, circling, rapid eye flicking, drooping on one side of the face, bleeding from the ear, a suddenly swollen ear flap, or a pet who is feverish, lethargic, or refusing food alongside ear symptoms. These can point to middle or inner ear involvement, which needs prompt attention to protect balance and hearing.
Frequently Asked Questions
How can I tell if my dog's ear infection is yeast or bacteria?
You can't reliably tell by looking; it requires a cytology swab examined under a microscope, which your veterinarian can do in a matter of minutes during the appointment.
Is it safe to use an over-the-counter ear cleaner before my appointment?
It's best to wait, since certain cleaners can worsen irritation if the eardrum is affected, and cleaning right before the visit can also wash away debris your veterinarian needs to see for an accurate diagnosis.
Can allergies from Utah's dust and pollen cause ear infections in dogs?
Yes. Environmental allergens common in the region, including pollen and dust, are a leading cause of recurring ear infections in dogs, and the ears are sometimes the only place the allergy shows up.
How long does it take for a dog's ear infection to clear up with treatment?
Most pets look noticeably better within a few days, but the full prescribed course (often one to three weeks) needs to be finished and confirmed with a recheck, since stopping early is the most common reason infections come back.
Are certain dog breeds in St. George more prone to ear infections?
Yes, breeds with floppy ears or heavy coat around the canal, such as spaniels, retrievers, and hounds, trap heat and moisture more easily, which raises their risk regardless of local climate.
If your dog or cat has been shaking, scratching, or just seems a little "off" around the ears, reach out to the Washington Family Vet Clinic team. Our St. George veterinary staff offers otoscopic exams, in-clinic cytology, and full ear cleaning and treatment plans to get your pet comfortable again quickly. Contact Washington Family Vet Clinic today to schedule a visit.
Book an Appointment or call us at (435) 627-1300.