Ear Infections in Cats: Causes and Symptoms

Cats like nothing more than to give themselves a good groom, so seeing your feline friend relaxing, licking his paws to clean his ears, and occasionally scratching his head seems like nothing more than natural feline behaviour.

However, if he is persistently scratching his ears and shaking his head, that could a pretty clear sign that his ears are causing him some discomfort.

Certain cats are more prone to ear infections than others.

If your cat is allergy-prone, has a weaker immune system or spends a lot of time outdoors, and especially if he is in contact with other cats, then he is more likely to catch ear mites or develop an ear infection than one who spends more time at home.

If you do spot signs of an ear infection, it is essential that you get your cat to the vet for diagnosis and treatment as soon as possible to minimise pain and long-term damage to his ear canal.

Most ear infections are easily curable, especially if treated quickly, but if left they can become chronic and could even lead to deafness in the infected ear(s) and in some extreme cases - even facial paralysis.

To help you differentiate between the common ear infections in cats, here is a guide to seven of the most common problems, their causes and symptoms.

Ear Infections In Cats Affecting The Pinnae


Mange (often referred to as feline scabies) is a highly contagious skin infection caused by the Notoedres cati, a mange mite, which seems to prefer to live on the skin surrounding the head and ears of cats.

Mites are the cause of many cat ear infections, as we will cover later.

The signs of mange are severe itching on the pinnae (ear flaps) and behind the ears.

The skin in the infected area becoming thick, scaly and covered with crusts, causing such intense itching that cats will scratch so badly they cause wounds.

If left untreated this will often spread over other parts of the body.


Cats who go outside, or live in an area where there are other cats, are more than likely to get into the odd fight, and this often results in bite and claw wounds, particularly to the pinnae (ear flap).

These lacerations or punctures can then become infected; bite wounds are especially prone to infection.

Apart from being very painful, an abscess can cause fever and tiredness, and loss of appetite in your cat until the infection has cleared up.

Of all the fight wounds, bite wounds are especially prone to causing abscesses because of the number of bacteria in cats’ mouths.

An abscess usually appears as a painful, fluid-filled lump under the skin.

There may be a small scab or puncture wound near the lump, but an abscess isn’t always obvious and isn’t spotted until it breaks open and starts oozing pus.

Ear Infections In Cats Affecting The Ear Canal: Otitis Externa

Infections affecting the ear canal are called ‘otitis externa’; this is the term used to cover inflammation and infection of the ear canal and pinnae (ear flap), not a specific disease.

Ear Mites

Ear mites are responsible for about 50% of all cat ear problems.

The most common ear mite is Otodectes Cynotis; they are tiny parasites, about the size of a pinhead, they are highly contagious, and easily spread from cat to cat, and even to other pets.

Ear Mites are mostly found inside the ear canal and can cause severe irritation and itchiness along with inflammation which, if left untreated, could then lead to secondary ear infection problems.

The mite eggs are laid in the ear, and take about three weeks for them to develop into mature adult reproductive mites.

Although ear mites live primarily in the ears, they can also move to other areas of the body, which can then cause irritation of the skin as well.

It is important not to let this condition go on for long because your cat’s constant itching and scratching can cause not only discomfort but the scratching can also cause hair loss and skin irritation around the infected area.

Bacterial or Fungal (Yeast) Infections

Bacterial infections, bacterial otitis, often occur as a secondary symptom of other ear problems such as ear mites, a foreign body, trauma or skin allergy; however, many cats can just develop ear infections without there being any underlying cause.

These include bacterial or fungal infections that can cause pus, and even blood, to build up in your cat’s ear canals which can cause him to tilt his head and imbalance, so he is unable to walk in a straight line.

Although bacterial and fungal infections often look quite similar to ear mite infestations; your cat will display the same scratching of his ears and shaking his head, but looking closely at his ears you will notice some differences.

If a cat has an ear infection, their ears tend to become more red and swollen than when they have a mite infestation, probably with heat in and around the ears, and there will be more discharge from the infected ear(s).

The discharge usually has a distinctly unpleasant odour.

If an ear infection is left untreated, it can become chronic and possibly cause deafness in the infected ears.

Polyps & Tumours

Ear polyps or tumours are not a common problem, but if not properly diagnosed they can cause severe damage to your cat’s ears.

They are small nodules which can develop in the skin lining of the ear canal and/or the middle ear.

Polyps are benign (safe) growths, and tumours are malignant growths.

Although it is not fully understood why polyps suddenly develop, they seem to occur as a result of long-term inflammation caused by bacterial or fungal infections, and frequently cause secondary infections, which may be the first sign that your cat has a problem.

Ear Infections In Cats Affecting The Middle and Inner Ear

Infections that affect the middle ear (otitis media) often also affect the inner ear (otitis interna), causing imbalance; affected cats often hold their head to one side and have difficulty walking, or walk round in circles towards the affected side.

If the eardrum (tympanic membrane) is damaged, infections from the middle ear can also spread up to the outer ear canal or vice versa.

Fortunately, if detected early, most inner and middle ear infections can be treated successfully.

The most common conditions are:

Infection of the Middle / Inner Ear

The symptoms of a middle or inner ear infection are similar to those of an outer ear infection outlined already: itching ears, head shaking, unpleasant smelling discharge, etc.

However, because the middle and inner ear coordinate hearing and control balance your cat will probably also show signs of hearing loss and imbalance.

As the middle ear infection progresses, your cat could then start to develop facial paralysis on the infected side because the facial nerve runs next to the ear and can also become inflamed.

This will cause drooping eyelids and the third eyelid partially covering the eye; he could also show signs of loss of appetite because of the lack of use of his facial muscles causing him difficulties when eating.

When the infection is in the inner ear, he will start to have mobility problems due to the disturbance of the ear’s control of balance.

The symptoms will include disorientation, loss of balance, a downward head tilt and even circling.


Polyps are benign inflammatory growths that can appear in a cat’s middle ear or eustachian tube (a small tube that connects the middle ear with the back of the nose, allowing air to enter the middle ear) and can cause cats to develop middle ear infections.

Although most common in young adult cats, cats of any age may be affected.

If a polyp develops in the middle ear, there is a danger that it could eventually cause the eardrum (tympanic membrane) to rupture, enabling any infection to travel up to the ear canal.

Final Thoughts

The best way to ensure you catch any ear infections in your cat early is to routinely check his ears to make sure there are no signs of redness, discharge or odour.

Healthy ears are a pale pink colour and have no visible discharge, odour and little or no wax.

Checking your cat regularly will ensure that you detect any ear infections early so you can get treatment before it develops into a more serious problem.

About the Author Kate Davis

Dr Kate Davis is a veterinarian with almost ten years of experience. Dr Kate has always had an affinity for cats, so it was a short step for her to become a cat writer.

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