Signs of ear mites in cats, and what to do about them

A cat that suddenly cannot leave its ears alone, scratching hard enough to shake its head, flatten an ear back, or dig at the same spot repeatedly, is telling you something is actively irritating it. Ear mites are one of the most common causes, especially in kittens and cats with outdoor access, and they are easy to miss at a glance because the mites themselves are too small to see. What you can see, once you know what to look for, is the mess they leave behind.

The tell that separates mites from ordinary wax

Every cat produces some ear wax, and a small amount of pale, faintly waxy debris on a cotton pad after a gentle check is completely normal. Ear mites produce something different: a dark brown or black, dry, crumbly discharge that is often described as looking like coffee grounds, sitting deeper in the canal than routine wax and usually building up fast once mites are established. It typically comes with a distinct, unpleasant smell and noticeably more debris than a healthy ear produces between cleanings.

Alongside the discharge, watch for the behaviour that usually brings owners to check in the first place: persistent scratching at one or both ears, frequent head shaking, an ear held flatter or lower than usual, and dark scabbing around the outer ear from repeated scratching. Mites are intensely itchy, and a cat with a bad infestation can scratch hard enough to break the skin or cause a haematoma, a painful blood-filled swelling in the ear flap, from the trauma of its own scratching.

Why they spread so easily

Ear mites are highly contagious between cats through direct contact, which is why they turn up so often in kittens from shelters, busy multi-cat households, or a household that has recently taken in a new cat or a stray. They can also cross species, passing to dogs and other pets that share close contact, bedding, or grooming with an infected cat. This matters for treatment as much as for prevention: treating only the cat showing symptoms while another household pet carries mites untreated is one of the most common reasons an infestation appears to clear and then comes straight back.

Why a vet check matters before treating

Scratching and dark ear debris are not unique to mites. Bacterial infections, yeast overgrowth, and allergies all cause similar itching, and each produces a somewhat different discharge and needs a different treatment. Grabbing an over-the-counter ear product without knowing which of these you are dealing with risks masking symptoms without actually clearing the underlying problem, and it can delay a cat getting the right treatment for weeks. A vet can usually confirm ear mites in minutes with a quick swab examined under a microscope, which is a small step that saves real guesswork.

Once mites are confirmed, treatment is generally straightforward: a prescribed topical medication applied over several weeks, since mite eggs hatch in stages and a single treatment rarely catches every generation. A gentle ear cleaner such as an ear cleaner made for cats is often used alongside the prescribed treatment to help clear debris so the medication can actually reach the skin, though it does not replace the treatment itself and is worth checking with your vet before adding to the routine.

When to get your cat seen

Book a vet visit for any cat showing persistent ear scratching, head shaking, or dark, gritty discharge that does not clear up within a few days, rather than waiting to see if it resolves on its own. Get your cat seen the same day if you notice a swollen or misshapen ear flap, a strong odour with visible pus, or a cat that seems in obvious pain when its ear is touched, since these point toward complications that need prompt attention rather than routine treatment. Left untreated, ear mites cause ongoing distress and open the door to secondary bacterial infections that are harder to clear than the mites alone would have been.