Chronic Ear Infections in Cats

Do you know ear infections are less common in cats than dogs?

Whereas one in five dogs suffers an ear infection, for cats this is more like one in fifty. This is great news for cats as a sore ear makes life a misery; however, for those affected its vital not to overlook or ignore it.

The Ear: More Than Meets the Eye

Anatomically speaking, the feline ear is divided into three parts:

• The External Ear: This includes the ear flap (pinna) and the ear canal.
• The Middle Ear: This sits behind the ear drum and contains three tiny bones that push against the entrance to the inner ear, converting sound waves into electrical energy.
• The Inner Ear: This transmits that electrical energy to the brain where it’s heard as sound, plus it houses the balance organ that helps a cat stay upright on her paws.

This is part of why seeking urgent treatment is important: Not only are ear infections irritating and painful, but if left they can track inwards and cause serious such as balance problems or permanent deafness.

Chronic: A Long Term Problem

In case you were wondering, the word ‘chronic’ means ‘long term’. Thus a chronic infection has rumbled on for weeks, but can be mild or severe. However the nature of chronic ear infections is they tend to be severe as they are often the result of an overlooked mild infection which has deteriorated.

What are the Signs of a Long Term Ear Infection?

Most cat guardians are eager to help their pet, so it’s helpful to know the signs to be alert for:

• Head Shaking
• Scratching the Ear: The cat may rub her head, or when you fuss her ear it induces frantic scratching with a back paw.
• A Discharge: This can range from excessive amounts of brown wax through to smelly yellow-green gunk
• A Bad Smell: A healthy ear should not smell
• A Narrowed Ear Canal: If in doubt compare one ear with the other to see if they are both the same size. The narrower ear canal is the one with the problem.

What Causes Ear Infections in Cats?

Most ear infections start off with inflammation. For example, the cat scratched her ear, this set up inflammation which weakened the skin’s local immune system which couldn’t keep the normal surface bacteria in check, which allowed them to colonize the canal.

There are certain factors which can predispose a cat to ear infections and these include:

• A humid environment
• A weak immune system
• Over enthusiastic ear cleaning
• Inflammation of the skin lining the ear canal

However to truly get to grips with the problem and stop it recurring, it’s necessary to delve even deeper and ask: “What caused the inflammation / weak immune system / high humidity in the first place?”

What Causes Inflammation?

Allergies are just one reason the skin linking the ear canal becomes inflamed. This can be food allergy or a reaction to the environmental factors such as pollen, mould spores, or dust. Also, scratching the ear because of fleas can cause skin inflammation.

What Causes Itchiness?

Ear mites, yeast, or excessive numbers of bacteria are all sources of itchiness. It’s thought around 50% of ear infections in cats are caused by ear mites, so this is especially common. Part of the reason is the ear mites stimulate the ear to overproduce wax (that thick black wax you could grow potatoes in) which is the ideal food for the mites, hence creating a perfect haven.

What Causes Humidity?

When you soak in the bath for too long, your fingertips go all wrinkly. This is known as ‘maceration’ and is a product of the skin swelling in the presence of moisture. A similar softening of the skin occurs inside the ear canal, when the humidity level is high.

The commonest cause of high humidity in a cat’s ear is narrowing of the ear canal. In turn, this is most frequently caused by polyps or swollen cerumen glands, which then constrict the width of the canal, decrease air circulation, and increase humidity.

How Does the Vet Diagnose the Cause?

The vet looks for underlying factors by looking into the ear with an otoscope. In addition, they may put samples of wax under the microscope to look for the presence of eggs, mites, yeasts, or bacteria.

If a bacterial infection is suspected, the vet may swab the ear and send the sample away for culture to find out exactly which antibiotic is the right one to use. This is especially useful for infections that have rumbled on for a while and nothing seems to clear them up.

What Treatments are Available?

Where possible the vet treats the underlying cause. So for ear mites this could mean using a monthly spot-on anti-parasite product containing selamectin, to kill the ear mites. Alternatively, anti-fungal or anti-bacterial drops are put directly into the ear to fight infection.

If an underlying allergy is suspected then the vet may suggest putting the cat onto a hypoallergenic diet for two to three months, to see if the cat improves during this time.

If the ear canal has become severely and permanently narrowed, then corrective surgery may be necessary in order to open up the ear canal and lower the humidity levels.

And finally, it’s always best to get your cat checked by a vet if you are suspicious of an ear infection. From the surface only a tiny proportion of the ear canal is visible, and looking deeper with an otoscope is essential. Remember that overlooking an ear infection can allow it to rumble on and become chronic. . . risking serious consequences such as deafness or poor balance. . . So let’s ‘ear it for healthy hearing.