Ear infections in cats: symptoms, causes and what to do

🐈 Cats · 🧴 Care & grooming · updated 2026-08-27

Green-eyed tabby cat settled on a sofa

An ear that gets scratched more than usual, a head held tilted to one side, or an unfamiliar smell from the ear flap: these discreet signs deserve attention, since ear infections are under-diagnosed in cats compared with dogs. A study by Ginel, Lucena, Rodriguez and Ortega, published in 2002 in Veterinary Dermatology, compared cytological samples from healthy and diseased ears in cats and dogs, and showed that routine microscopic examination reliably distinguishes a healthy canal from an inflamed one, well before signs become visible to the naked eye (search on Google Scholar). Find all our health guides in the cat care and grooming category.

What signs should raise concern?

A cat that shakes its head frequently, scratches an ear enough to create scabs, holds its head tilted to one side, or gives off an unpleasant smell from the canal shows signs typical of an ear infection. The inside of the ear flap may also redden or develop an unusual amount of brownish wax, distinct from the small amount of pale wax normally present.

What are the most common causes?

In kittens and young cats, ear mites, the tiny parasites behind "ear mange", remain a very common and highly contagious cause between housemates. In adults, an ear infection can also stem from a food or environmental allergy, a foreign body such as a grass awn, a yeast overgrowth, or, more rarely in older cats, an inflammatory polyp deep in the canal. Without an otoscopic and cytological exam, these causes are difficult to tell apart from symptoms alone.

What to do while waiting for the vet visit

Our guide to cleaning a cat's ears covers the preventive routine to adopt once the episode clears up.

Frequently asked questions

Does a cat's ear infection clear up on its own without treatment?

Rarely completely: without treatment matched to the underlying cause, the inflammation tends to persist or recur, with a risk of progressing to the middle ear if left untreated for too long.

Are both ears always affected at the same time?

No, an ear infection can easily affect only one ear, especially with a foreign body or a localised polyp, while a parasitic or allergic cause more often affects both sides.

Should a cat with ear mites be kept apart from other cats?

Only if it lives with other cats, for the duration of treatment: ear mites spread easily through direct contact between housemates, even asymptomatic ones.

This guide is part of Planète Pets’s Cats universe. Our advice is general in nature: for any health concern, your veterinarian remains the only reference.

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