Why do my cat's ears smell?
A cat's ears should not have a noticeable smell. When they do, it is almost always a sign that something is growing where it should not — wax, yeast or bacteria building up in the ear canal — rather than a normal variation between cats. It is rarely an emergency, but it is very rarely nothing either.
Usually not urgent
This is common and often manageable at home — but see a vet if it persists, gets worse, or comes with other changes.
What a smelly ear usually means
The most common cause in cats is a build-up of wax and debris that has allowed yeast or bacteria to multiply, producing the smell along with a darker discharge than usual. This can follow water getting into the ear, allergies, or simply a cat whose ears trap more debris than most.
Ear mites are another common cause, particularly in kittens and cats that have spent time around other cats, and tend to produce a dark, coffee-ground-like discharge alongside the smell and visible irritation. A vet can confirm this quickly by looking down the ear canal, which is not something you can reliably tell from the smell alone.
Other signs worth noticing alongside the smell
Watch for your cat shaking their head, scratching at one or both ears more than usual, holding their head tilted to one side, or reacting when the base of the ear is touched. Redness, swelling, or visible discharge inside the ear canal are all worth mentioning to your vet along with the smell itself.
A cat who is otherwise bright, eating normally and not obviously bothered by the smell is a different picture from one who is scratching constantly or clearly uncomfortable. Both are worth a vet visit, but the second is worth booking sooner rather than waiting to see if it settles.
Why it is not something to leave
An ear infection left untreated can spread deeper into the ear canal and become more painful and more difficult to clear, and in some cases can affect a cat's balance if it progresses far enough. What starts as a mild smell can become a much bigger problem for your cat, and a more expensive one to treat, the longer it is left.
It is also not something to guess at home. Ear infections in cats have several different causes — mites, yeast, bacteria, allergies, and occasionally a foreign body such as a grass seed — and the wrong home treatment for the wrong cause can make things worse or mask what a vet needs to see.
What a vet visit usually involves
A vet will typically look down the ear canal with an otoscope and may take a small sample of the discharge to check under a microscope for mites, yeast or bacteria, which decides what treatment is appropriate. This is a quick, low-stress check for most cats and gives a much clearer answer than smell alone ever can.
Book a vet appointment if the smell has appeared suddenly, has not settled within a few days, or comes with any of the signs above. Do not put anything down your cat's ear canal — cleaning solution, oil, or a cotton bud — before a vet has looked, since some substances and techniques can make certain causes harder to diagnose or treat.
Ongoing ear care once the cause is treated
Once a vet has identified and treated the underlying cause, they may suggest a routine ear-cleaning product suitable for cats to use occasionally afterwards, particularly for a cat prone to repeated build-up or known allergies. This is different from treating an active infection yourself, and it should only start once a vet has confirmed there is nothing else going on.
Some cats are simply more prone to ear problems than others because of their ear shape, allergies, or general skin sensitivity, and for these cats a vet may suggest checking their ears as part of a normal grooming routine so a build-up is spotted early rather than after it has already started to smell.
What can help
Things we stock that owners commonly use alongside a vet’s advice — not a substitute for it.
Leucillin Antiseptic Skincare Spray for Cats & Dogs
A versatile, alcohol-free antiseptic spray that cleans, soothes, and helps protect your pet's skin from bacteria, viruses, and fungi.
From£7.99
Absorbent Cotton Gauze Swabs for Pets – Pack of 100
Highly absorbent, low-lint cotton gauze swabs produced in clean conditions — a practical first-aid essential available in three size and ply combinations.
From£4.49
3M Synthetic Under Bandage Padding for Pets
A soft, breathable non-woven polyester padding layer designed to protect and cushion beneath bandages on dogs and cats.
From£9.49
Little Friends Trimmed Dried Cuttlefish Bones
Trimmed dried cuttlefish bones for birds, reptiles and small pets, a natural calcium source
£9.99
Common questions
- Is it normal for a cat's ears to smell a bit?
- No, a healthy cat's ears should have little to no noticeable smell. Any distinct odour, particularly a sour or yeasty one, usually means wax, yeast or bacteria has built up in the ear canal and is worth mentioning to your vet rather than treating as normal.
- Can I clean my cat's smelly ears myself before seeing a vet?
- It is better not to. Some cleaning solutions and techniques can make it harder for a vet to identify the underlying cause, and if the cause turns out to be something like a perforated eardrum, certain products can make things worse. Let a vet look first.
- How do I know if it's ear mites?
- Ear mites typically produce a dark, crumbly discharge that looks a bit like coffee grounds, along with scratching and head shaking. A vet can confirm this in minutes by looking down the ear canal, since mites are visible under an otoscope.
- Will a smelly ear clear up on its own?
- It is unlikely, and leaving it risks the infection spreading deeper into the ear canal, becoming more painful and harder to treat. If the smell has lasted more than a few days or your cat is scratching or shaking their head, book a vet appointment rather than waiting.
- Can allergies cause smelly ears in cats?
- Yes, allergies are a recognised contributor, since they can lead to inflammation in the ear canal that lets yeast or bacteria multiply more easily. A vet can help work out whether allergies are playing a part alongside treating the immediate infection.
Related
Sources
Written against guidance published by UK veterinary and welfare organisations. Always confirm specifics with your own vet.
Written by Matt Garnett, who runs Giddy Pets and is a lifelong pet owner — not a vet. This is general information, not veterinary advice, and it cannot replace an examination by the vet who knows your animal. How we write these guides.