Allergies are a common cause of itchiness in dogs and cats. Although more commonly seen in dogs, allergies can effect cats as well. Common presentations are head shaking, scratching at the ears or body, or chewing the paws. These conditions will often respond well to over-the-counter medications or symptomatic relief but frequently return quickly. Let’s take a closer look at some of the more common causes of allergies in pets and how to best manage them.
Allergies can be due to fleas, environmental allergens, or food. Thankfully, with so many pets on regular flea and tick prevention medications, we do not see as many flea allergy cases as we used to. Environmental and food allergies are very common, however.
Environmental allergies can be from outdoor sources such as weeds, trees, and grasses. Dogs or cats with these allergies will typically have a seasonal pattern for their itchiness symptoms. We also see some indoor environmental allergens like dust mites and food storage mites. Food storage mites live on dry grain products including dry pet food kibble, but also on foods we eat like cereal, breads, and cheeses. These mites do not affect humans, but some pets can be very sensitive to them.
Dogs or cats with environmental allergies, whether indoor or outdoor in nature, tend to have itchiness all over their body. Some pets with grass allergies will only lick their feet, as this is where their body is contacting the offending allergen.
Food allergies are typically reactions to the protein source in the food, most commonly chicken or beef. It doesn’t matter how expensive or fancy a diet is, if a pet is sensitive to that protein, we will see allergy symptoms. Pets with food allergies will typically be prone to ear infections and/or problems with their anal glands but will sometimes be itchy all over like pets with environmental allergies.
Diagnosing allergies, especially differentiating food allergies from environmental allergies can be difficult, time consuming, and expensive. If environmental allergies are suspected, there is a blood test that can show us which environmental allergens are part of the problem. Unfortunately, there is not a specific test for food allergies. We will typically do a diet trial using a special type of diet containing hydrolyzed proteins. These are protein molecules that are broken down into smaller fragments in order to bypass the immune system that is on the lookout for larger protein molecules. It can take a few months to see positive results from these hydrolyzed diets. Once the pet is doing better on the new diet, we can confirm the allergy by challenging with the old protein source to see if the itchiness comes back.
Treatment of environmental allergies varies depending on what a pet is allergic to. Some allergens, particularly indoor allergens like dust mites, can be addressed by removing old bedding, couches, or rugs from the home. This may be enough to alleviate some pets’ symptoms. Food storage mites can be addressed by either switching to a canned food diet or by freezing the dry kibble to kill these mites. For allergens which cannot be removed from a pet’s environment, like most trees, grasses and weeds, we can formulate allergy injections or sublingual drops to gradually desensitize the immune system to the offending allergens.
Other treatment options can be utilized that are aimed at alleviating the symptoms of itchiness. For dogs, oral medications like Apoquel can block the pathway of itch sensation to keep them from reacting to the underlying allergy and causing more trauma to the skin by scratching or licking. There are injectable medications like Cytopoint that work by a similar mechanism that can be given for dogs who either do not take oral medications well or for pet owners who may not remember to give medications regularly. Both of these options typically need to be given long-term during a pet’s seasonal allergy period to prevent a recurrence of the itchiness. For cats, there are fewer symptomatic options, but often steroids can be used for short courses to alleviate itchiness and discomfort.
Other medications may be necessary to treat secondary skin or ear infections. As dogs and cats scratch, lick, or chew when they are itchy they can cause trauma to the skin, which creates a breakdown of the normal protective skin barrier. This can allow bacteria and yeast, which normally just live on the surface of the skin, to get a deeper foothold and cause a secondary infection. Topical antibiotics or antifungals can be helpful, but oral versions of these medications may be necessary in cases of more widespread infections. Topical products for ear infections are often also indicated, as well.
It is important to note that allergies are a life-long condition for pets. There is never a permanent cure or fix. Even dogs or cats that are well-controlled on a hydrolyzed protein diet or allergy injections will still have flare-ups from time to time. Our goal is to have these flare-ups be infrequent and of low severity. We strive to manage these conditions to keep them as comfortable as possible, because in the end that is what we all want for our pets!
