
That head shake means something: ear infections 101
Written by Dr. Cassie Knapp, DVM
Co-Founder & Chief Medical Officer, UrgentPaws
Published August 11, 2026
The short version
- Ear infections are genuinely painful. Head shaking and scratching are not habits — they are your pet telling you something hurts.
- A veterinarian needs to look inside the ear before treating. Some medications are harmful if the eardrum is ruptured.
- Do not use leftover drops from a previous infection or a home remedy. The wrong treatment makes the next examination harder to interpret.
- A head tilt, loss of balance, or an eye flicking side to side suggests deeper involvement and should be seen promptly.
What you are seeing
- Head shaking, or tilting the head to one side
- Scratching at the ear, or rubbing it along furniture and carpet
- A noticeable odor
- Discharge — brown, yellow, or black — or visible redness inside the flap
- Flinching, pulling away, or crying when you touch the ear or the area beneath it
- A swollen, spongy ear flap, which can follow vigorous head shaking
Why they happen so often here
An ear infection is usually a symptom rather than the whole story. The overgrowth of yeast or bacteria that produces the discharge and the smell tends to be secondary to something else: allergies, moisture, ear anatomy, or occasionally a foreign body.
Allergies are the most common underlying driver we see, and Southern California’s long allergy season means we see a lot of them. Add swimming, beach trips, and dogs with heavy drop ears that hold moisture and warmth, and the conditions are close to ideal. Foxtails deserve a special mention — a grass awn in the ear canal causes sudden, intense, one-sided distress and needs removing.
What treatment looks like
Most ear infections are handled in a single visit: examination, a sample, a thorough cleaning, and medication chosen for what we actually find. Pain relief matters here more than people expect — inflamed ears hurt, and a comfortable pet is far easier to medicate at home.
Finish the full course even after the signs disappear. Stopping early is the most common reason an infection returns within weeks, and repeated cycles can cause the canal to thicken permanently, making every future infection harder to resolve.
When to be seen promptly
- A head tilt, stumbling, circling, or eyes flicking side to side — this suggests the middle or inner ear
- Sudden, severe, one-sided pain, particularly after a walk in dry grass
- An ear flap that has swollen up firm and fluid-filled
- Any discharge containing blood
- A pet in enough discomfort that they cannot settle or sleep
Preventing the next one
- Dry the ears gently after swimming or bathing
- Use a veterinary ear cleaner at the interval your vet recommends — not more, since over-cleaning irritates
- Never insert a cotton bud into the canal; it pushes debris deeper
- Treat the underlying allergy if there is one, as that is what stops the cycle
- Check ears after walks in dry grass during foxtail season
Dr. Cassie Knapp, DVM
Co-Founder & Chief Medical Officer
Dr. Cassie Knapp is a veterinarian with 17 years of clinical experience and extensive emergency room and urgent care experience. See full bio
