Dog ear infections- what’s the real cause?

dog ear infectionsI spent a lot of time working in vet clinics this summer, and as usual, saw one thing over and over again. Dog ear infections.

Everything from mild redness and just barely starting to build up debris and smell, to the full out swollen, ruptured eardrum (if we can even see it), copious amounts of debris, that you can smell from 10 feet away. I saw them all.

I mean, it’s summer, they’re all swimming. So of course they’re getting ear infections.



Since summer is just starting to wane down and I’ve still seen more than a few in the last week or so, I wanted to take some time today to talk about ear infections and their causes.

The anatomy of the dog ear

Humans have a fairly straight ear canal. If you have a light, you can look in, and you can see the eardrum pretty easily.

Not so much with dogs.

Dogs and cats have an L shaped ear canal. Sort of. We call it L-shaped, and it sure feels that way when you’re going to look inside it, but technically it’s just more curved. (You can see a good diagram here.)

This means that when there is an infection, we have to make sure to treat all the way to the bottom of the canal.

The common causes of dog ear infections

Very commonly, if people have never seen an ear infection in a dog, they assume it’s just ear mites. Often, they’ve already tried to treat with over-the-counter ear medication.

However, ear mites are actually not that common. They’re also extremely itchy and almost always affect both ears (and are most common in cats from shelters).

If you can stick your nose down there and smell a bready sort of smell, chances are very good it’s a yeast infection. Yeast infections do often need medication to be treated, so I do recommend taking them in to the vet, but you also want to make sure you clean them out really well with ear flush. You can watch a good video on how to clean ears here.

So what actually causes a yeast infection?

There are 3 common causes.

  • Technically they can be caused by swimming too much (or for dogs like Boomer, sticking their head in the snow in the winter).
    • Anything that results in water getting into the bottom of that ear canal can be a problem, as that water is just a nice little sauna for bacteria and yeast to grow. Therefore, if your dog likes to swim (or stick it’s head in the snow or be groomed…), make sure you flush the ears out afterward! (See above for the best way to do this!)
  • There can be anatomical problems.
    • The ear is supposed to clean itself out, moving anything that is not supposed to be there up out of the canal to the outside. In some dogs, particularly with chronic ear infections, the ear canal can be pretty tight and swollen so this problem doesn’t work as effectually. There has also traditionally been thoughts that long droopy ears (think hounds and labs) and hairy ears (poodles, other hairier breeds) played a factor. We even used to pluck the hair from ears. We now know that this can cause MORE inflammation in the ear! The real answer in my opinion? Neither droopy ears nor hair are the common culprits. Really, we just blame them instead of finding the real problem. Hence common cause #3.
  • Dog ear infections are caused by food allergies.
    • Yes, for real. One of the most common causes of yeast infections is an allergy to something in the food. This doesn’t mean that the other components like hairy ears can’t play a part, but if they’re making it worse, it’s likely because the ear infection was already starting. Boomer used to get ear infections every single month, but he’s a lab and we had a pond in our backyard so I attributed them to both floppy ears and swimming excessively. However, as soon as we got his food allergies under control, the ear infections went away. Yes, almost all of them. He might get one a year now, usually after we board him overnight and they give him all sorts of treats.

Well, how do we know what they’re allergic to?

That’s the big question of the day.

And it’s not a simple question to answer, because every single dog is different. So here’s are my recommendations when you’re dealing with this.

The absolute first thing I recommend is to CUT THE GRAINS.


Put them on a grain free diet.

Why? Because grains are one of the most common sources of food allergies in my experience. I have yet to cut the grains from a dog and not seem some level of improvement. (Worried about the recent studies of grain free and heart disease? Read my post here.)

Furthermore, when you pick a grain free food, you’re also cutting all sorts of dyes, preservatives, and other less savory ingredients that tend to be included in lower quality foods.

Yes, grain free diets are usually more expensive. But trust me, they’re cheaper than constant ear medication (which is NOT cheap), or worse case, having to have surgery on the ear!

Once you’ve cut the grains, you have to be patient. When we’re dealing with food allergies, it can take between 2 to 6 months to see results. Luckily, it’s not usually that long. But you have to give it at least a minimum of 2 weeks, without making any other changes!

And yes, this is hard. Patience is hard when we’re trying to figure out what’s wrong and give the body time to heal. I’ve been through this.

But when you’re dealing with food allergies, patience is vital.

So cut the grains, then give it time.

If that’s not enough improvement, then you’re looking at more experimentation. They can be allergic to anything from the vegetables to the proteins, and some dogs just can’t handle the extreme processing of dry foods. So if you get to that point, you often have to experiment, listen to your gut, and see what you can figure out. (Yes, if you get desperate, there are allergy tests. I usually leave everything other than muscle testing to absolute last resort, as I don’t find they’re very accurate.)

What the moral of the story today?

If your dog gets constant ear infections, look at the food!

Has your dog experienced ear infections? What did you do to help them?

4 replies
  1. Donna
    Donna says:

    I had a German Shepherd that used to get ear infections frequently until I started feeding grain free. My sweet Buddy has since crossed the Rainbow Bridge, but none of my many other dogs over the years have ever gotten ear infections because I continue to feed grain free. It’s unbelieveable to me that I’ve mentioned this to veterinarians and they disagreed that the grain was the culprit. I don’t care what they think. I know that once I quit feeding grains, no more infections. I believe that the starch in the grains feeds the yeast. Just my opinion.

    • Dr. Jenny
      Dr. Jenny says:

      Unfortunately we’re taught that the grains can’t be the issue, and it’s hard to look outside of the box when we’re taught such strong opinions… The starch definitely doesn’t help, but the grains are also very inflammatory so they contribute that way too. All around, just better to not feed them!

  2. Andrea
    Andrea says:

    In my breed, Shar SharPei, it can be a few things. I get owners to get them on a raw diet if possible or grain and potato free diet. Probiotics and digestive enzymes are a must to help clear the toxins. I also make them.get rid of toxic scented candles, plug ins , sure fresheners, fabric softeners, highly scented detergents, carpet powders and toxic cleaning products. Going all natural made a huge difference for my old girl and my youngsters are better for it. No issues with this crew at all.

    • Dr. Jenny
      Dr. Jenny says:

      Yep, I love using probiotics and digestive enzymes to help the inflammation go down as well. Glad to hear yours are all doing well!


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