When a dog begins shaking its head nonstop, scratching an ear, or yelping as the ear is touched, the cause might be an ear infection—but it could also be a foreign object, injury, or inflammation from another problem. A new, painful ear should be checked rather than treated blindly at home.
Start by watching, not probing
Notice whether the dog is scratching one or both ears, whether there is an odor or discharge, and whether the ear flap looks red or swollen. Do not insert cotton swabs or try to reach down into the canal. The eardrum cannot be evaluated reliably at home.
If your dog has been swimming, mention that when you call the clinic, but do not assume trapped water is the complete explanation.
Why the veterinarian needs to see the ear
Infections involving bacteria or yeast may require different medication. Ear mites, allergies, foreign material, and damaged eardrums change treatment decisions. A veterinarian can use an otoscope and examine a swab of discharge under the microscope when indicated. Painful ears sometimes require extra care to examine safely.
Leftover ear drops may be expired, inappropriate for the cause, or unsafe if the eardrum is not intact. Do not use peroxide, alcohol, vinegar, essential oils, or human ear medication without veterinary instructions.
Signs that should be assessed urgently
Sudden loss of balance, pronounced head tilt, abnormal eye movements, difficulty walking, facial weakness, or severe pain with swelling warrants urgent veterinary evaluation. Middle- or inner-ear disease and neurological conditions can have overlapping signs.
If the ear flap balloons into a soft swelling after vigorous head shaking, this may be an aural hematoma; a veterinarian should evaluate it. Do not puncture or drain swelling at home.
What you can do while arranging care
- Keep the dog calm and limit scratching, using a well-fitted protective collar if needed.
- Keep the ear dry and avoid swimming or bathing until assessed.
- Photograph visible discharge or ear-flap swelling without causing pain.
- Follow only current medication instructions written for that dog and that episode.
After treatment, the clinic may want to recheck the ear to confirm infection and inflammation have resolved. Dogs with recurring episodes may need investigation for allergies or other underlying disease, not just repeated drops.
For prevention after recovery, see our dog ear infection prevention guide. Our ear emergency signs guide covers signs involving balance and severe pain.
Questions dog owners ask
Can ear infections start overnight?
Signs can become noticeable suddenly, even when irritation was developing earlier. A veterinarian needs to determine the cause.
Will the ear clear up if I clean it repeatedly?
Not reliably. Cleaning the wrong way can cause more irritation, and infections or foreign objects may need targeted treatment.
Source: Merck Veterinary Manual: ear infections and otitis externa. Educational content only.
This article is for general education and is not a substitute for care from your own veterinarian. Learn about The Pet Vet and our editorial policy.