Food Allergies in Dogs & Cats

Many people have allergies and it’s no fun to have them. Maybe you have a mild allergy, perhaps to pollen. In the spring and summer you sneeze and your eyes get red and runny. You can take some medication that makes it a little bit better but often you can never entirely get rid of your allergies. Perhaps you have a severe allergy, like a peanut allergy where even a microscopic piece of peanut could cause you to die within minutes. Would you be surprised to find out that many pets have allergies too? Severe allergies are uncommon in dogs and cats. It’s true that some pets can be severely allergic to a drug, but this is fairly rare. Mild allergies however, are fairly common in pets.

In fact it seems that the number of pets with allergies is increasing. Perhaps this is because we are breeding pets that have a greater risk of allergies. It could be that our pets are being exposed to chemicals that can help create allergies. Maybe there always were a lot of allergic pets but we never recognized their allergies. We really don’t know why allergies are becoming more common in people and in pets but many suggest that environmental factors are the primary ones at play.

What is an allergy anyway? An allergy is when the body overreacts. The body will come into contact with a substance (it could be in the environment or in food) and suddenly targets that substance as an invader. In an allergic reaction the body creates an unnecessary war against a normally harmless substance (allergen). The symptoms of allergies (in humans these symptoms can be anything from sneezing to the inability to breath) are not directly caused by the allergen. The symptoms are a result of the body’s excessive reaction to the harmless allergen.

In pets, there are two big categories of allergies; environmental and food related. Just like some people can be allergic to latex, pets can be allergic to anything from a plastic water bowl to a household cleaner. Pets can also have the same type of environmental allergies as humans; for example, they can have allergies to a wide variety of pollens. Environmental allergies can cause many different signs, but most often cause itching. This itching is often located in places where the pet can interact with the environment, such as the face, paws, and belly.

Food allergies are sometimes even trickier to diagnose than environmental allergies. Pets tend to have allergies to foods that are commonly found in pet foods, such as beef, corn, and wheat. Just like pets with environmental allergies, food allergies tend to cause itchy skin. The itchy skin due to food allergies, is often found in different parts of the body than itchy skin due to environmental allergies. But food allergies can still look a lot like environmental allergies. Pets with food allergies can also have intestinal problems and persistent diarrhea.

Which pets get allergies? Dogs definitely get diagnosed with allergies more frequently than cats. Young and middle aged dogs are the most at risk for developing a new allergy. So how do we diagnose an allergy? Your pet can be diagnosed with an allergy either at your local veterinarian or at a dermatologist. Most likely your pet will go through quite a bit of testing before the allergy is brought under control. One thing to keep in mind is that, with allergies, it often takes months to figure out what is wrong and to fix it. Often the veterinarian will first rule out other causes of itchy skin like parasites, behavioural issues, or other skin disorders.

The veterinarian may chose to do a variety of tests. They may take a skin biopsy to look at under the microscope. They can also take a skin scraping. Very often the veterinarian will want to do blood work as well. At a referral centre, a dermatologist can even do the allergy testing, just like they do with humans. The veterinarian will inject a small amount of different types of allergen under the skin and look for a reaction. If your pet has environmental allergies to an object, like plastic, often all you have to do is remove the object. If the environmental allergy is seasonal, like pollen, the veterinarian will commonly give allergy medication during those seasons. Food allergies are a little bit harder to deal with. Pets with food allergies are often put under a ‘food trial’. This is a fairly long process (months) where different foods are fed at home until the veterinarian can determine what the pet is allergic to. After that, the pet is put onto a food that does not contain the food that causes an allergy.

As mentioned above, allergies usually take months to treat. Sometimes a certain treatment will work for a few years, and then will stop working. Then the veterinarian has to find a new solution. Treatment of allergies can be very frustrating for the owner when nothing seems to work. But treatment of allergies is also very satisfying and will help your pet live a happier life. With a little bit of patience, you and your veterinarian should be able to find something that works for your pet.

By Ashley O’driscoll – Pets.ca writer