Ear Mites and Ear Infections in Cats: Catching Them Early

Quick answer

Most cat ear problems are caught by noticing behaviour, not by looking down the canal.

Cats get ear infections far less often than dogs. When a cat does have an infected ear, there is usually a reason underneath it, and finding that reason matters more than treating the infection once.

In kittens and in cats from multi-cat, shelter or outdoor backgrounds, ear mites are the usual answer. In a single adult cat with one bad ear, a polyp, a foreign body or a growth moves up the list.

• Ear mites are intensely itchy, usually affect both ears, and spread readily between cats, dogs and ferrets.
• One ear affected in an adult cat is a different problem from both ears affected in a kitten.
• Dark debris is not automatically mites. Mites, yeast and bacteria look alike and need different drugs.
• A head shaking cat with a smelly ear needs a vet, not a cleaning session at home.
• Head tilt, circling, wobbling or flicking eyes means the problem has reached the middle or inner ear. That is a same-day call.

:::danger
Do not treat a suspected ear infection with anything you already have.

If the eardrum has been damaged, and infection, polyps and foreign bodies all damage eardrums, then cleaners and many ear medications reach the middle ear and can cause permanent deafness or severe balance disturbance.

Leftover drops from a previous episode, a product prescribed for a dog, or a bottle bought without a prescription can all be the wrong drug for the organism present, and applying the wrong one delays proper treatment while the ear deteriorates.
:::

Decide in 60 seconds

Why cats are not small dogs here

Recurrent otitis is a routine part of canine practice. It is not a routine part of feline practice, and that difference is diagnostically useful.

Dogs have anatomy and allergic disease that predispose them to repeated ear infections. Cats mostly do not. So when a cat turns up with an inflamed, discharging ear, the sensible question is not just which bug is growing but what let it grow.

That is why a good consultation for a cat ear involves an otoscope, a look at the debris under a microscope, and often imaging if the ear does not respond as expected. Treating a cat's ear infection without asking why is how polyps and foreign bodies get missed for months.

Ear mites

Ear mites are the most common infectious cause in cats, and overwhelmingly the most common in kittens.

The mites live on the surface of the ear canal. They do not burrow. They feed on skin debris and tissue fluid and provoke an intense inflammatory reaction, which is why an infested cat is so much itchier than the amount of visible disease suggests.

What it looks like. Dry, dark brown or black, crumbly debris, often in both ears. Constant scratching at the ears and shaking of the head. Scratch wounds and scabs behind the ears and down the neck. In heavy infestations the itch spreads and the cat may groom at the head and neck generally.

Who gets them. Kittens, cats from litters, rescues, shelters, colonies and outdoor cats. Adult indoor cats can get them from a new arrival or from a dog.

Why treating one animal fails. Mites move between animals in close contact. A treated cat sharing a bed with an untreated cat or dog is reinfested within days. Every cat, dog and ferret in the household needs treating together, on veterinary advice, even the ones with no signs.

People. The mites can occasionally cause a transient itchy rash on human skin, but they do not establish on people. If several animals and a person in the house are itchy, mention it to both your vet and your doctor.

Treatment. A prescription parasiticide, chosen by your vet, applied on their schedule. Cleaning alone does not kill mites, and over-the-counter drops are frequently ineffective against them.

The itching can persist for a while after the mites are dead, because the inflammatory reaction takes time to settle. Do not assume the treatment failed and start something else without asking.

The causes that need more than drops

Inflammatory polyps. These are benign growths that arise from the lining of the middle ear or the tube that connects it to the throat. They are seen most often in young cats. A polyp growing outwards fills the ear canal and causes one-sided discharge, head shaking and sometimes a visible pink mass at the ear opening. A polyp growing the other way, towards the back of the throat, causes noisy breathing, snoring, sneezing or difficulty swallowing instead. Polyps are removed surgically. Repeated courses of ear drops will never resolve one, and a cat with an ear that improves on treatment and relapses every time it stops deserves a look for one.

Foreign bodies. Grass seeds and awns are the classic culprit in outdoor cats during the summer. The signs are sudden and one-sided: violent head shaking, pawing at the ear, obvious distress in a cat that was fine an hour earlier. A seed migrates inwards and can perforate the eardrum. Removal is usually straightforward and usually needs sedation.

Growths and cysts in the canal. Older cats can develop dark, blister-like cystic swellings in the ear canal lining, and less commonly tumours of the wax glands. Any mass in the canal of an older cat needs assessment rather than treatment by drops.

Allergic and other skin disease. Less common in cats than in dogs, but real. Ears usually appear alongside itching elsewhere, particularly the face and neck.

Systemic disease. A cat with poor immune function, from illness or from immunosuppressive medication, tolerates organisms a healthy cat would clear.

When it has gone deeper

The middle and inner ear sit behind the eardrum. Disease that reaches them produces a different, unmistakable set of signs, and they justify a same-day appointment.

Head tilt. The head is held persistently to one side, usually the affected side.

Loss of balance. Circling, stumbling, leaning, falling to one side, or an inability to walk in a straight line.

Flicking eye movements. The eyes jerk rhythmically, often side to side. This is not something a cat can do voluntarily and it is always significant.

Nausea. Drooling, refusing food, and vomiting, from the vertigo.

A drooping upper eyelid, a constricted pupil, a raised third eyelid and a slightly sunken eye, all on one side. This combination arises from disruption of nerves that pass through the middle ear, and in a cat with ear disease it points strongly at what is happening behind the drum.

Facial weakness. A drooping lip or ear on one side, or an eye that does not blink properly.

These cats often need imaging, and treatment is longer and more involved than for a simple outer ear infection. Getting there early is what protects hearing and balance.

The early signs that come before all of this

The record is the diagnosis. Dates of head shaking, which ear, and what was applied when, told plainly, save a lot of guesswork.

Cats conceal discomfort, so the useful early signals are small and behavioural.

Head shaking that has become a habit. Not the single shake after waking, but repeated shaking through the day.

Scratching behind the ear with a hind foot, repeatedly. Look for the result of it: broken hairs, scabs, or a thin patch at the ear base.

One ear held slightly lower, or flicked more than the other. Cats do this before there is anything visible in the canal.

Pulling away when that side of the head is stroked. A cat that has always enjoyed being scratched at the ear base and now ducks the same touch is telling you something.

Debris that comes back. If the ear looks dirty again a few days after being cleaned, cleaning is not the answer and something is producing it.

A change in sleeping posture. Some cats stop sleeping on the affected side.

A new smell. You will often smell a cat ear problem before you see it. Cat ears should have no odour at all.

What the appointment involves

Expect an otoscope examination of both ears, including an attempt to see the eardrum. A painful cat may need sedation for this, which is not a sign of overcaution: a proper look at a sore ear cannot be done on a struggling cat, and a partial look misses polyps and foreign bodies.

Expect a swab taken for microscopy. This is what decides the medication.

Expect questions about every other animal in the home.

Expect imaging to be suggested if the ear does not respond, if the disease is one-sided and persistent, or if there are balance or facial signs.

What never to do

Do not use leftover ear drops from a previous episode, from another cat, or from a dog.

Do not buy an over-the-counter ear treatment for suspected mites without a diagnosis. Many are ineffective against mites, and applying one to an ear that actually has a polyp or a foreign body wastes weeks.

Do not flush or clean a painful, discharging ear at home.

Do not use oils, vinegar, hydrogen peroxide or any home remedy. None of them kill ear mites, and several damage inflamed tissue.

Do not treat only the itchy cat when mites are diagnosed. The untreated housemate becomes the reservoir.

Do not ignore a head tilt or unsteadiness for a few days to see if it passes.

Do not assume an ear that has stopped smelling is cured. Finish the course your vet prescribed and go back for the recheck, because an ear that looks better on the surface can still be inflamed round the bend where you cannot see.

When to get help

Contact your vet the same day for a head tilt, circling, unsteadiness, flicking eye movements, a drooping eyelid with a small pupil on one side, facial weakness, or sudden violent one-sided head shaking.

Book an appointment this week for any smell, discharge, dark crumbly debris, redness, pain on touch, persistent head shaking, or scabs around the ear base.

Book promptly for a swollen ear flap, a visible mass at the ear opening, or an ear problem that keeps coming back after treatment.

Ears carried level and evenly, no shaking, no smell. That is the endpoint, and it is worth going back for the recheck to confirm it.

Go back for the recheck even if the cat seems well. The visible part of the ear improves before the deep part does, and stopping early is one of the main reasons cat ear disease becomes chronic.

Check the neck and the fur behind the ears at the same time. Scratch damage there is often visible before anything shows in the canal.