Gazette Vet: Allergic Skin Disease


Does your dog lick or chew his feet a lot? Does he have perpetually “dirty” ears? Does she suffer from skin rashes or hair loss? Is her skin often covered with scabs and crusts?

Answer ‘yes’ to any of these, and the odds are you’re in the same (crowded) boat as many other pet owners whose pets have allergic skin disease.

Allergic skin disease significantly affects the quality of life of more dogs (and their owners) than any other disease out there. By far. Cats also suffer, just not as frequently.

I’ve got my fair share of allergies (I definitely chose the wrong profession to be allergic to dogs and cats!) and would be a sneezing, congested mess if it weren’t for my Zyrtec and Flonase. But I can’t say my hands and feet get itchy or that my ears and skin are constantly getting infected.

That’s where our pets are a bit different from us. They are generally allergic to the same things as we are (plus a few extras like fleas and mange), but they show it differently. Dogs and cats with allergies tend to get itchy skin, which often leads to skin and ear infections.

When you’ve ruled out fleas (more on that another day, but let’s just say if your pet is not on a quality flea product like Frontline, it may be fleas!), the most common cause of allergic skin disease in dogs and cats is atopy—which I call allergy to Virginia.

Atopy is when the immune system is overreacting to everyday things (aka allergens) out there—pollens, grass, dust, mold. But instead of the typical “hay fever” signs we see in people, dogs and cats get skin disease. For whatever reason, when they are exposed to an allergen—let’s say ragweed pollen—that allergen reacts with their immune system and ultimately causes histamine release. Good ol’ histamine-creator of redness, itching, and swelling. Whereas our histamine release from the ragweed pollen generally occurs in our nasal passages and leads to sneezing and a runny nose, the histamine release in dogs and cats tends to occur throughout their skin. Sometimes it’s localized to certain areas like the paws and ears, but often times it’s all over.

Ok, so my dog is itchy. He’ll live … right? Well, itching is really only a part of it. It’s the secondary skin infections that cause all the appointments I’m going to see tomorrow, and the next day, and the day after.

Like it or not, we’re all a big Petri dish, growing millions of lovely types of bacteria and yeast all over our bodies. When all is well, this occurs in a balance, and we’d never know we were so infected.

But let’s take the dog with the ragweed allergy. He’s having a heck of a time lately and histamine is being released all over his skin. He is chewing at his feet like crazy and his skin is generally inflamed and a bit pink (under all that fur). Well, inflamed skin means warm skin—and all those bacteria and yeast that live on the skin and down in the ears, well, they just love it a few degrees warmer! So they start to grow and grow. The next thing you know, you’ve got an overgrowth of normal skin bugs which have now caused an “opportunistic infection.”

That itchy dog has gone from just being a bit annoying because he’s waking you up with that incessant, steady licking of his feet, to now being a dog who has open sores on his belly and is constantly shaking his head from the yeast infection in his ears.

So what can you do? Well, it’s worthwhile to call your vet. Each allergy case is different and requires its own unique approach. We’ve got to rule out fleas, think about possible food allergies (which look the same as “Virginia” allergies), and also clear up any infections that may be present.

We often use antihistamines, but to be honest, they’re often disappointing. They help my allergies tremendously, but don’t seem to really keep too many dogs out of the office. But they are safe and can help some, so they’re worth a try.

Any secondary infections like “hotspots,” rashes, or ear infections need to be treated with an appropriate antimicrobial. Chronic cases can take weeks to months to clear up.

Ultimately, steroids are often necessary in many allergy cases. Steroids are a Godsend for allergic pets. They are extremely effective in stopping allergic inflammation, giving animals rapid relief, and helping secondary infections clear up quicker. Unfortunately, they have their share of side effects and they need to be used judiciously. Generally, the side effects associated with “anti-allergy” doses are mild and rapidly subside once the steroids are stopped, but dogs who require longer courses require more discussion about potential side effects (which are still generally mild and totally reversible).

I haven’t gotten into allergy testing, desensitization, food allergies, fleas, and other important allergy topics, but there’s always another month. Many of you reading this have been through it all too many times with your own pets and unfortunately know your vet’s phone number by heart. But if you’ve been wondering why your dog won’t stop licking its feet in the middle of the night, he’s not crazy, he’s just itchy!