Vet Blog

Allergies

February 24, 2022

Have you ever awoken in the middle of the night to the sound of a thumping foot scratching at the neck, flapping ears, jangling collar tags, or my personal favorite, the slurping sounds of a pup going to town on its paws, belly, or rear end?

A surprising number of people will answer yes to this question. All of these behaviors can actually be indicative of an underlying allergy in our pet and the distress (and sleepless nights) it causes for those affected can be heartbreaking. If you've ever had a pet with allergies, you may be aware of the skin infections, ear infections, redness and flaking of the skin, watery eyes, hair loss, and the funky odor that often accompanies them. However, you may not be aware that your dog's favorite "tickle spot" or that classic skin crawling or foot thumping response that you see when you scratch his or her neck or back may also be a sign of itchy skin that may be due to an underlying allergy.

In pets, we usually see two different types of allergies: those to food and those to triggers in their environment (although we can see BOTH in the same pet). Contrary to current popular belief, food allergies are rarely due to carb or grain sources in pet foods such as corn, rice, or wheat, but rather to the animal protein in their diets. Chicken and beef tend to be our biggest culprits, but due to the growing popularity of fish-based diets, we're seeing more and more fish allergies as well. Interestingly, food allergies in pets can manifest in many different ways, but more commonly we see recurrent ear infections (yeast and bacterial), itchy skin sometimes accompanied by infections or hair loss, and occasionally gastrointestinal signs such as soft stools, diarrhea, vomiting, and gassiness (aka dog farts). These signs usually persist throughout the year without any improvement during the colder winter months. There are several tests out in the market that claim to be able to diagnose a food allergy with a cheek swab or blood test, but there has yet to be a clinical study that has proven those tests to be reliable. The only proven method we have to diagnose an allergy to food is to do a strict hypoallergenic or novel protein diet trial. This involves putting your pet on a special diet and eliminating ALL other foods, treats, and even flavored medications for at least 2 months. Hypoallergenic diets have been favored by dermatologists in the past because the protein source in those foods is broken down into such small fragments that the body can't recognize it as an allergen and over 90% of dogs with food allergies will have a beneficial response to these diets. We're leaning more towards using foods that have a limited ingredient profile and what we refer to as a novel protein source, meaning your pet has NEVER been exposed to this protein before (think: ostrich, kangaroo, crocodile, rabbit, wild boar, venison, etc). Unfortunately, with this method we can only tell you IF your pet has a food allergy. In order to figure out which ingredients trigger the itch, we have to reintroduce each item one at a time and play the wait and see game. However, most pets with food allergies can be controlled with diet change alone once we identify the problem.

Environmental allergies are a whole different beast. While a majority of pets with environmental allergies are sensitive to pollen from outdoor plants such as trees, grasses, and weeds, it's possible for pets to be allergic to things in the indoor environment including dust, linen fibers, bird feathers, molds, cats, and even people. Yes, your dog can be allergic to you. While indoor allergens tend to persist throughout the year (sometimes making it difficult to differentiate from a food allergy), most environmental allergies are seasonal. Your pet is normal and comfortable in the late fall and winter months, but come springtime that skin begins to itch and that foot begins to scratch. Controlling the
discomfort, itchy skin, and skin infections that often occur as a result is usually our primary concern. This is often achieved through careful use of oral antibiotics, topical therapy with shampoos, sprays, mousses, and wipes, and medications to help control the itch. The meds we've used in the past have usually been antihistamines (variably effective), steroids (catabolic, not the 'roid-rage anabolic ones) or some form of an immunosuppressant. Obviously, these medications can have serious side effects in our patients but, unfortunately, had been our only source of relief for the intense itch. Recently, there has been an influx of new products into the market which help control itch more safely and effectively than either steroids or medications that suppress the immune system. Most of these newer options start working in as little as 24 hours, which can be an immense source of relief for both our patients and their owners. Injectable forms can even last as long as 2 months after a single injection. Some pets will need to use these medications seasonally when they are most affected, but often we're looking at a lifetime of medications. For this reason, I often have my clients consider allergy testing. A simple blood test can let us know what environmental allergens your pet has and we can use that information to get their immune system to decrease or even stop reacting to those particular triggers. This often involves giving injections or a liquid oral drop in order to expose your pet to the allergens in greater and greater quantities in order to build tolerance. This is the closest thing that we have to a "cure" for allergies, but some pets need immunotherapy for many years before we can achieve the desired effect. However, for very young or severely affected pets, it's definitely worth the effort.

Allergies are a horrible condition to deal with. Dermatologists have long equated skin allergies in dogs to eczema in people because the rashes, intense itch, and damage caused to the skin are very similar. We can treat infections easily enough, but unless we address the underlying cause, they will just keep coming back. If you feel your pet has any of the above mentioned clinical signs, please have him or her evaluated by your veterinarian. There are so many treatment options available and, although it may not be an easy road, the prospect of uninterrupted beauty sleep for both you and your furry baby may just be worth it.

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