Any new smells coming from your cat are causes for concern, as they often are symptoms of decay, infestation, or infection. Stinking fur, bad breath, and changes to stool odor each could be signs of different conditions that require quick medical intervention. What about when the fetid, putrid smell comes from your cat’s ear or ears? Is it likely something serious? The short answer is YES. A more nuanced answer is only slightly less worrying: it may not be something serious, but unless you take action quickly, it will become serious very soon.
Primary Cause: Infestation
The most common cause of ear infections in cats is an infestation of ear mites. These infestations cause over half of all feline ear infections and are highly contagious, spreading through direct contact with infected animals, but also through indirect methods: contact with the toy or bed of an infected animal. They can also spread from animals of a different species, so dog toys and leashes are also possible points of transmission.
Fortunately, the mites leave humans alone.
Telltale signs of an ear mite infestation include head-shaking, excessive scratching around the ear, and hair loss around the affected area. There is also often a dark, sticky, coffee-ground-like discharge from the ear that carries with it a foul, unpleasant odor.
The mites themselves cause great discomfort to your cat, but are they truly dangerous? If untreated, the answer is yes, very. The infestation can spread to the rest of the body, leaving crusted, scaly, damaged skin, and it can also turn inward and rupture the eardrum. Untreated, the infestation can cause secondary infections of the outer ear, mutilation of the ear due to scratching, and permanent damage to the cat’s sense of balance. It can also cause a hematoma of the ear, which will require a visit to the vet to be drained.
Because the mites are microscopic, a diagnosis from your veterinarian is a must. Not only will the vet be able to confirm the presence of the mites and determine the severity of the infection, but you can find out for sure if there are secondary conditions already active.
While at the vet’s office, you will likely be prescribed an FDA-approved medication to kill the mites. The vet will advise on follow-up treatment, both with this medication and with the proper cleaning methods. You will need to clean your home thoroughly to ensure that no mites survive by hiding in bedding and toys, and if you have other animals, keep the infected cat in isolation.
Extra Note of Caution
While keeping your cat’s ears properly cleaned can prevent mites from forming an infestation, improper cleaning can cause otitis externa and otitis media.
Primary Cause: Otitis Externa and Otitis Media
Either as the primary cause of your cat’s smelly ear or as a secondary infection, otitis externa and otitis media refer, respectively, to outer and inner ear infections.
Otitis Externa, inflammation of the outer ear, is the general medical term for an ear infection, and can have many different causes. A mite infestation is one such cause, although your cat could have an ear infection without mites and mites without an ear infection. Regardless of which is the base cause, you would smell something fetid and decaying from your cat’s ear.
Other causes of an outer ear infection can be bacterial, fungal, environmental, excessive moisture, or allergies. The symptoms are generally the same as with a mite infestation, so when your cat begins the head-shaking and ear-scratching, have your vet do the diagnosing. Cultures, scans such as X-rays and MRIs, and microscopic exams. Skin-scrapings may be examined to check for parasites and biopsies may be run to check for an autoimmune condition. If the cause is bacterial, cultures to determine which bacteria are the culprits are necessary to ensure correct treatment.
Untreated, Otitis Externa may spread, leading to Otitis Media, an infection of the middle ear. This infection is often very difficult to treat, resistant to medicine, is difficult to diagnose (middle and inner ear infections do not show up on an X-ray), and if untreated, can lead to deafness, balance issues, and the need for “total ear canal ablation,” or the surgical removal of the entire ear canal.
Treating Otitis Externa requires correct diagnosis. If the underlying cause is an external factor, such as mites or an autoimmune condition, those must be treated alongside the infection itself. Then, it is imperative to know if your infection if fungal, bacterial, or a combination, and which fungus or bacteria. Follow your vet’s orders precisely, and be sure to make and keep a follow-up appointment. William Miller Jr., VMD, sums up the severity succinctly:
If you don’t identify the cause and deal with it appropriately, the infection may clear up temporarily but will come right back after treatment is stopped.William Miller Jr., VMD
Lady Lulu and the Seven Year Itch
A perfect example of Dr. Miller’s statement is as follows.
I have been gifted with the care of a beautiful tabby cat, Lady Lulu, for seventeen years now. Found abandoned under a dumpster at approximately four weeks old, she has been a valued companion to me. When she was about four, she developed feline asthma. Later, when she was about ten, she began suffering recurring sinus infections.
Because she already had a pre-existing respiratory condition, her bad colds and sinus infections were always treated as minor, secondary issues by the vets she saw; she was given a general antibiotic for a respiratory infection and a short-term steroid to soothe her asthma flare.
As time went on, these infections became more frequent and more severe. Remarkably, all of her tests–x-rays and bloodwork–showed a very healthy cat, healthier than expected for her age. Finally, her current veterinarian decided that a cat her age shouldn’t just get increasing steroid doses. Something else must be wrong. He ran several tests and concluded that, rare as it was, Lady Lulu suffered laryngeal paralysis and would require a special surgery to keep her throat open; he believed it was less an infection or asthmatic flare that was causing her troubles, but something muscular.
The specialist, however, believed her struggles to breathe were from the head, not the throat. Exams of her outer ear showed no indications of distress whatsoever. He decided to take a step no other vets had taken, though, and ran a CT scan, the result of which showed a middle ear full of fluid. He drained it and sent cultures out to determine just what we were dealing with, but the general result was unexpectedly this: the level of damage there suggested this infection had been there for several years. It had survived multiple courses of antibiotics. It had escaped the diagnosis of multiple veterinarians.
Poor Lady Lulu had been dealing with a middle ear infection for seven long years, and it had been misdiagnosed as complications from feline asthma.
To treat such a persistent infection, she required two full months on a strong antibiotic. Her balance never faltered, but her hearing is completely gone now. Still, she has bounced back with a fury, now that she had the correct diagnosis. Even with consistent, regular care, this infection went unnoticed for almost a decade. Without regular care, the effects would have been much worse, much faster.
She is now recovering, walking without a wheeze and sleeping more easily than she had in quite a while; her breathing had become so difficult that the vet’s supposition is that she burned so many calories even in her sleep from the force required to breathe that she had lost a dangerous amount of weight. Now she eats, she sleeps, and she doesn’t hear, but she has energy and affection again.
Will my cats ear infection go away on its own?
No. The infections have many possible causes, are uncomfortable and dangerous for your cat, and will not go away on their own. See your vet right away!
What causes ear infections in indoor cats?
If your cat hasn’t been exposed to parasites like mites or ticks, an indoor cat may be more susceptible to infections if they have an underlying cause like an autoimmune condition, allergies, or diabetes.
Are some cats more prone to ear infections?
Although any cat can suffer an ear infection, some breeds are more susceptible than others. In particular, cats with small ears, like Persians and Himalayans, are more prone than others.
A smelly cat is never a joke. Talk to your vet immediately if any strange smells start coming from your cat’s ears; even if the smell is from something minor, the longer you wait, the more dangerous it will become, and it will not go away without the proper care.