Ear infections are one of the most frequently diagnosed conditions in dogs — accounting for a significant portion of vet visits every year. The good news is that the symptoms are usually noticeable before the infection becomes serious. The key is knowing what to look for.
Common Symptoms of a Dog Ear Infection
Head shaking. One of the first signs. If your dog is shaking their head more than usual — especially repeatedly or intensely — something is bothering them in the ear canal.
Scratching at the ear. Dogs with ear infections often scratch at the affected ear with their back paw, or rub their ear along the floor or furniture trying to relieve the discomfort.
Odor. A noticeable smell coming from the ear — often described as yeasty, musty, or foul — is a reliable indicator of infection. Healthy dog ears have very little odor.
Discharge. Brown, yellow, or black discharge in or around the ear canal. The color and consistency can hint at the type of infection — dark brown/black discharge often indicates yeast or ear mites; yellow or green suggests bacterial infection.
Redness and swelling. The ear canal and the skin inside the outer ear may appear red, inflamed, or swollen. The ear may feel warm to the touch.
Sensitivity or pain. Your dog may pull away or cry out when you touch or examine the ear. Some dogs become reluctant to have their head touched at all when an ear infection is present.
Tilting the head. A dog that holds their head tilted to one side may have an infection or discomfort in the ear on the lower side.
Balance problems or unusual eye movements. These suggest the infection has moved to the middle or inner ear — a more serious situation that needs prompt veterinary attention.
What Causes Ear Infections in Dogs?
Ear infections in dogs are most commonly caused by yeast (Malassezia) or bacteria, and sometimes both at the same time.
Several factors make dogs prone to ear infections:
Ear shape. Dogs with floppy ears — Cocker Spaniels, Basset Hounds, Golden Retrievers — have reduced airflow into the ear canal, creating a warm, moist environment where yeast and bacteria thrive. Dogs with narrow ear canals have a similar issue.
Allergies. Skin allergies (food or environmental) are one of the most common underlying causes of chronic or recurring ear infections. The inflammation from allergies affects the skin lining the ear canal, making it more susceptible to infection.
Moisture. Dogs that swim frequently or are bathed often without thorough ear drying are more prone to ear infections. Water trapped in the canal creates ideal conditions for microbial growth.
Ear mites. More common in puppies, ear mites cause intense itching and produce a dark, coffee-ground-like discharge. They're highly contagious between pets.
Foreign objects. Grass seeds and other debris can lodge in the ear canal and trigger infection.
Hormonal imbalances. Conditions like hypothyroidism can make dogs more susceptible to skin and ear infections.
Types of Ear Infections
Otitis externa — infection of the outer ear canal. The most common type and the most straightforward to treat.
Otitis media — infection of the middle ear. Often develops when an outer ear infection goes untreated. May cause more significant pain and balance issues.
Otitis interna — infection of the inner ear. The most serious type, affecting balance and hearing. Requires aggressive treatment.
When to See a Vet
Any suspected ear infection warrants a vet visit. Ear infections don't resolve on their own, and attempting to treat them without knowing the cause can make things worse — a yeast infection and a bacterial infection require different treatments. Using the wrong medication can allow the wrong organism to thrive.
See your vet promptly if:
- Symptoms have been present for more than a day or two
- The ear smells strongly or has visible discharge
- Your dog is in obvious pain or won't let you near their ear
- You notice balance problems, head tilt, or unusual eye movements
- It's a recurring problem (may indicate underlying allergies)
Can You Prevent Ear Infections?
Not entirely, but you can reduce the risk:
- Dry ears thoroughly after swimming or bathing
- Clean ears regularly with a vet-recommended ear cleaner (not cotton swabs deep in the canal)
- Keep hair around the ear opening trimmed in heavily coated breeds
- Address underlying allergies with your vet if infections recur
The Short Version
Head shaking, scratching, odor, and discharge are the main things to watch for. If you notice any combination of these, it's a vet visit — not a wait-and-see situation. Ear infections are common, very treatable when caught early, and progressively harder to manage if left alone.