Modern Medicine, Old-Fashioned Care

May 11, 2023 | General Health

What Causes Ear Infections in Dogs and Cats?

Ear infections in dogs and cats are a common presentation at veterinary clinics, says Doylestown Veterinary Hospital’s Dr. Mimi Fitchett, DVM.

Wherever there’s a dark, moist environment – bacteria and yeast can grow, so infection can develop.

“Microbiome is the new buzzword for every part of our bodies, right? Well, the ear has its own normal microbiome,” Dr. Fitchett says. “It has its own normal skin turnover. And if any of those things are disrupted for some reason – if that normal barrier has some type of disruption, whether it’s infection or allergy – you’re going to be predisposed to having organisms grow in that area.”

The Truth About Cats and Dogs – And Infection 

The usual suspects when it comes to ear infections in dogs and cats are typically food or environmental allergies.

According to the American Kennel Club, allergies lead to ear disease in about 50 percent of dogs with allergic skin disease and 80 percent of dogs with food sensitivity.

A veterinarian’s goal is to pinpoint those triggers and eliminate them – thus warding off future infection.

Parasites, such as ear mites, can also be a culprit, and frequently physiology comes into play.

“Often, dogs will come in with multiple infections, and then we need to investigate whether there are conformational issues in the ears,” Dr. Fitchett says.

Conformational concerns surround the shape of the ear canal, she explains.

“Some breeds – particularly really short-faced dogs, or what we call brachycephalic, like a bulldog or a Frenchie – have ear canals that are conformationally abnormal.”

In other words, a whole lot of “stuff” is shoved into a much smaller space, creating a squiggly path that is not only challenging to clean but also prone to recurring infection.

“Unfortunately, these kinds of dogs are also predisposed to allergies,” Dr. Fitchett says.

Not only that, “but if your pet has chronic and recurrent infections, they may be predisposed to the ear canal becoming calcified and narrower,” she adds. This conformational complication can also make ear infections more difficult to treat.

While the causes for ear infections in cats are typically the same as their canine cousins – allergies, parasites, and to a far lesser extent, conformation issues – our feline friends are somewhat unique when it comes to ear infections.

“Cats are super special, because, for one, there are far fewer medications available to combat ear infection that are labeled for use in cats.”

And, by and large, cats simply don’t get ear infections that frequently. “Which is a good thing,” Dr. Fitchett says. “But it can also make things more challenging sometimes.”

“Cats usually don’t want to have otoscopes put in their ears,” she says. “They don’t like to be poked and prodded. Especially if they’re already uncomfortable with an infection. So, it can be a little more difficult that way.”

Be Aware of the Signs of Infection

Dogs and cats both make ear wax just like people do, Dr. Fitchett says.

Some make more than others.

An abundance of ear wax doesn’t necessarily mean an infection is present, but if it is accompanied by a bad odor, a call to the vet is in order.

“The ears should sort of smell like the rest of your animal,” she says. “If you notice that funk kind of smell, that often indicates there’s a problem.”

Additional signs that your pet may be fighting infection include continuous head-shaking and incessant scratching at the source. Inflammation is also a red flag.

What Pet Owners Can and Should Do

Dr. Fitchett says one simple precautionary measure can include flea and tick medications that will remove mites as a probable cause from the start.

“A lot of the new oral and even some of the topical medicines can eliminate a variety of ear mites,” she says. “Putting your dog on a preventive treatment, can at least take mites off the table as a potential problem.”

Dr. Fitchett strongly urges against treating a dog or cat with OTC cleansers if an ear infection is suspected.

“I don’t recommend over-the-counter cleansers or treatments without having your pet evaluated first,” she says. “You want to make certain – as much as you can – that the eardrum is intact.”

Ear infections are the most common reason for ruptured eardrums in dogs.

“You can’t tell if your pet’s eardrum is about to rupture, but most of the time, you can tell if has ruptured already. The main thing is we don’t want to hurt an animal by using a medication that would make things worse.”

In other words, when in doubt, see your veterinarian.

“When dogs come in for a visit for ear infection, it’s routine for us to swab both ear canals and look at it under the microscope to assess for any abnormal organisms, like an overgrowth of yeast or different types of bacteria,” Dr. Fitchett says.

From there, multiple cleansers and treatments can be administered depending on the severity.

“Some you can do at home, and others we do here at the hospital,” she says. “It makes it easier. There are a lot more in-hospital treatments, now, so that the owner doesn’t have to have so much tough work.”

There are times when an infection is so extreme and painful, that other methods are required.

“We may treat with oral medications like steroids to bring down that inflammation so that we can recheck for a better evaluation” she says. “Sometimes, dogs have to go under anesthesia to have the ear canal thoroughly cleaned and evaluated. It’s not that common, thank goodness, for us. Those are more of the outliers than the day-to-day.”

Future Fixes

The initial consultation with a veterinarian, diagnostics, and proper treatment are all essential when dealing with ear infections in dogs and cats, Dr. Fitchett says. But equally important is the follow-up.

“We usually recommend a follow-up appointment a couple of weeks after treatment,” she says. “I’ve been surprised at the number of times where I’ve looked in an ear canal and said, ‘Oh, wow, that’s really looking good.’ And the owner feels like it’s looking good. But when we actually look at the cells on the slide, it’s not as perfect as we want it to be.”

Occasionally, healing simply takes a little bit longer than estimated. But that makes following up with the vet that much more important.

Admittedly, Dr. Fitchett says, ear infections are not the most exciting thing to discuss in the vast field of veterinary medicine. But for our dogs and cats, they’re a big deal when they happen.

“It’s like when you got an ear infection when you were a kid,” she says. “You remember how bad your ear hurt. It’s the same with our pets. It’s something you want to take care of.”