Ear infections (Otitis) in cats may not be as common as in dogs but they do happen quite frequently. It is a condition that cat owners need to be on the lookout for as they can cause a lot of pain and discomfort. A cat’s ear has to be very complex and intricate to allow them to detect sounds up to a frequency of 60 kilohertz. This is 40 kilohertz higher than a human can hear! Sadly, this intricacy also makes the cat ear prone to infections.
There are several different types of ear infection. If the infection is on the outside of the ear it is called Otitis externa. You would normally be able to see some visible signs of this. If the infection is further inside the ear, it is called Otitis media and if it reaches the inner ear it is referred to as Otitis interna. This is the most serious type of ear infection in cats and can lead to deafness if the tissues get very damaged.
The otitis may be present in one ear or in both ears at the same time. If it comes on suddenly, it would be termed an acute infection and otitis can go on for a long time and can become a chronic condition too. In general, younger cats tend to get them more often than older cats and they are very variable in severity. Some cat breeds, such as the Himalayan, are also more prone to ear infections.
What Causes Cat Ear Infections?
There are many different causes of cat ear infections and your vet will try to get to the bottom of what has caused the problem before they start any treatment. The environment of the ear and the ear canal is ideal for the growth of bacteria, viruses and yeasts because it is moist and warm and has plenty of nutrients. Anything that breaches the natural defences of the ear can open the door to opportunistic infections.
Around a half of all cat ear infections are caused by the cat ear mite which is called Otodectes cynotis. Kittens are especially susceptible and some adult cats are more sensitive to the mites than others. The mites cause irritation and as the cat scratches they can cause a lot of damage to the ear which becomes infected.
Mange mites usually affect other areas of the cat’s body but they can also irritate the ears.
Cats can be allergic to substances in their diet or to ingredients in their food. Often, ear problems in a cat are the first sign of an allergy. The allergic reaction alters the environment within the ear and secondary infections caused by bacteria or yeasts can set up. Some medications have been known to cause a similar reaction. It is important to identify the cause of the allergy to prevent the infection from recurring.
- Bacterial, Yeast and Viral Infections
Under normal conditions, your kitty’s ear will be able to fend off all of the bacteria and yeasts that are found in the environment. However, if the delicate structures of the ear become damaged by allergic reactions, hormone imbalances or even just excessive moisture, the natural defences can be breached. Several different types of bacteria (including E.coli) and yeasts (including Malassezia pachydermatis) can be involved. Viral infections can also play a role.
- Foreign Bodies
A foreign body is anything that gets into the ear that should not be there. Bits of plants (particularly plant awns and fox tails that are sticky) can cause a lot of irritation and trauma. Dirt, sand and even a lot of hair growing in the canal can cause the same problem. Rough cleaning of the ear area using inappropriate cleaning solutions can cause a similar effect.
When anything irritates the ear, a cat will tend to excessively scratch the area. This causes damage to the skin and delicate structures and a bacterial infection can set in. It can also happen during an accident or during a fight.
- Hormonal Problems
A kitty that has either too much or too little of a particular hormone often gets both skin and ear problems. Typical examples are the thyroid hormone (thyroxine) and glucocorticoids which are produced by the adrenal gland. An imbalance of the sex hormones can have the same effect.
- Abnormal Growths
There can be abnormal growths in the ear and in the ear canal that make it susceptible to infection. Cats can get ear polyps and malignant or benign tumours in their ears including squamous cell carcinomas and melanomas. There can also be unusually thick hair growth or a build-up of wax in the ear canal.
- Underlying Diseases
Your vet will want to confirm whether your cat’s ear infection is as a result of an underlying disease that can affect the body’s natural ability to fight off infections. Diabetes mellitus can affect the immune system and any of the feline immune suppressing diseases such as FIV or feline leukemia virus will need to be ruled out. Eosinophilic granulomas are a special type of growth that are related to the immune disorders of cats.
Preventing Cat Ear Infections
You can do a lot to prevent cat ear infections with a few simple precautions.
The obvious place to start is by controlling ear mite infestations as they cause so many cat ear infections. Most cats pick up mite infections when they are outdoors so you may want to try keeping your kitty inside as much as you can. Of course, they may not be too keen on this! Never introduce a new cat or kitten into your home without getting them checked out for ear mites. They could spread them to all of your other cats. If your cat insists on going out, you should treat them regularly with a product that will control parasites.
If you are unsure of how to clean your cat’s ears correctly, it is best to talk to your vet and ask them to show you. Simply cleaning and inspecting your cat’s ears regularly can help a lot. Kitties have an L-shaped ear within which debris can easily collect. You can buy special ear cleaners for cats which are slightly acidic but will not sting. Using the ear cleaner you massage the base of the ear for half a minute and this releases the debris. Then you just wipe out the loose debris that is in the excess fluid with a cotton wool ball. You keep repeating the procedure until all of the debris has been removed.
You must be very careful how you use cotton applicator swabs. They can be used to wipe the inside of the earflap and the top part of the ear canal that is visible. However, you must never try to poke them down further into the ear canal because you will simply push debris further into the canal rather than removing it.
It can be dangerous to clean your cat’s ears if they already have an infection or a ruptured eardrum as the liquid could enter the inner ear and cause more damage.
Many cats do not enjoy having their ears cleaned so you will have to find ways of calming them. You could try talking to them in a soft voice or giving them a treat. Most cats will shake their heads for a bit after they have had their ears cleaned and this is perfectly normal so don’t be alarmed.
This may not prevent an infection all together but it will help you to spot it in the early stages before it becomes more serious and harder to treat. You can expect to see a small amount of waxy build up but it should not be excessive. Normal, healthy ears should be a pale pink colour and have no obvious debris, odour or lesions. Things to look out for include:
- Foul discharge. Infected ears often ooze a discharge that can smell pretty awful!
- Pus or blood. There may be a lot of ear wax coming out of the ear and it may be mixed with blood or pus or both.
- Pain. You may notice that your cat flinches when you touch their ear or the area around the ear.
- Crusting, scaling and thickening. Otitis that is severe or that has turned into a chronic infection can cause the wall of the outer ear canal to thicken. This makes the opening to the ear very narrow and cleaning can be difficult.
- Inflammation. The ear canal may appear very red (erythema) and so may the ear flap. It may also feel warmer than usual when you touch it.
- Open lesions. The infection may have got to the stage where it causes breaks in the skin which look like ulcers.
- Head shaking. Watch out for more head shaking than normal or rubbing the head or ears on furniture or the floor
- Scratching. Your kitty cannot tell you that they are in pain but they will show it by clawing at the affected ear.
- Obvious wounds. Eventually, all of the scratching will result in visible wounds appearing around the ears and face.
Another sign of an ear infection in cats is a lack of balance and changes to their behaviour. Once the infection reaches the inner ear, it can cause the head to tilt and your cat may not be able to stand or walk. At this stage there may be severe hearing loss and a lot of pain and your kitty needs to see a vet as an emergency.
Treating Health Conditions
If you promptly seek treatment for issues such as diabetes and the immune disorders, they are less likely to cause ear infections in your cat.
Diagnosing a Cat Ear Infection
If you suspect that your kitty has an ear infection, it is important that they get treatment right away. The vet will make a thorough investigation which may include:
- Taking a comprehensive medical history. This will tell them how long it has been going on, how severe it is and whether there are any underlying medical conditions.
- A physical examination. This will indicate the extent and severity of the infection and may help to determine the underlying cause e.g. ear mites.
- Vets use a special tool called an otoscope to look into the ear canal (for growths and polyps) and to see the eardrum. Cats find this very distressing and most have to be anaesthetised.
- Your vet may examine discharge from the ear using a microscope to see if there are any mites. Staining procedures can be used to detect and identify bacteria and yeasts.
- Bacterial culture. The exudate from your cat’s ear can be cultured in a laboratory to find out exactly which bacteria or yeast are causing the problem. Then the laboratory can do tests to work out which antibiotics or antifungal treatment will be effective against that particular strain. This is called sensitivity testing
- Allergy testing and food trails. If it is suspected that an allergy is at the root of the problem, your vet may need to order some allergy tests. Food trials are not undertaken lightly because they can take a long time to complete. If your vet feels that a food allergy is causing the problem, a food trial will eliminate certain proteins from your cat’s diet. It usually takes about four months to complete.
The important thing is that the underlying cause of the infection is established. This will enable your vet to prescribe the right treatment and help your kitty to quickly feel a lot more comfortable.