The immune system is vital to the overall health of our pets. The immune system protects the body from almost all of the bacteria and viruses our pets encounter throughout their lives. For some of these serious diseases, we help the immune system protect them by giving vaccines to better prepare the immune system to fight off diseases. There is no doubt that the immune system serves an important function to the overall health of our pets, but sometimes it over reacts to things and causes problems. The most common example of this is allergies.

With this article, I wanted to focus primarily on allergies in cats because we now have a recently approved option for cats called Atopica for cats. Over the years I have been very frustrated how few products get approved specifically for cat problems. We have had Atopica available for dogs for quite a few years. Even though we knew that Atopica could be given to cats, it was an off label use and the capsules for dogs were difficult to get into a cat. Atopica is now approved and in a liquid form that can be given very easily to a cat.

Allergies are basically an over-reaction by the immune system to something a cat encounters in everyday life. It is something that really isn’t harmful to the cat otherwise, but for some reason the immune system just goes crazy when the cat is exposed to it. Some of the things cats can be allergic to include fleas and other insects, weeds, grasses, trees, molds, foods, and basically about anything else in life. Cats can show allergies similar to dogs with just red skin, itching and hair loss, but we do see some signs of allergies unique to cats.

It isn’t unusual for cats to come in with areas of hair loss on their belly or legs and the owners haven’t noticed them being itchy at all. Often the skin in these areas isn’t red at all. In these areas we will see short, broken off hairs. The hair in these areas are broken off from the cat excessively licking the area because it is itchy. When we see this, we know the cat is itchy even if the owner hasn’t seen them itching.

Sometimes allergic cats will come in with very small scabs found most commonly on their head, neck, and above their tail. Although the scabs start very small, some cats will itch at them so severely that they will get much bigger and start blending together to from very large, seepy sores that can eventually cover the majority of their body.

And finally, there are clinical signs often associated with allergies in cats grouped together as Eosinophilic Granuloma Complex. This is a specific type of inflammation often associated with allergies. This can show up as a very swollen chin, a large ulcer on the lip, a white plaque on the eye, or a red, raised sore found most commonly on the belly or back of a hind leg.

Although there are many options for treating allergies in cats, many cats don’t cooperate. After a week or two of popping pills, bathing, and spraying, even a mild mannered cat can get pretty upset and throw a major “hissy fit”. We often end up giving long- lasting cortisone shots every few months to these cats to keep them comfortable. Getting one of these cortisone shots a couple times a year is safe for most cats, but more than that can increase their risk for some infections and diabetes.

Atopica can be a great option for some allergic cats. It is considered an immune modulator and works by keeping the immune system from over reacting to things. It is a liquid that can be dosed to the cat’s exact weight and initially is given daily for 4-6 weeks. If it is working well, it usually can be decreased in frequency over time to be given as infrequently as twice a week. In a study of cats placed on Atopica, 78.6% were pleased with the results. The most common side effect noticed from Atopica is decreased appetite, vomiting, and diarrhea. If any of these are seen they usually resolve spontaneously even if medicine is continued. Contraindications are primarily related to the fact that Atopica does affect the immune system. Cats with any history of any malignant or possible malignant disorders should not be put on Atopica. Cats should also be Felv and FIV negative and should be kept indoors to decrease the risk of exposure to other infections.

Chad Higgins, DVM has owned Amanda Animal Hospital for the past 15 years. He sees dogs, cats, ferrets, and other little furry critters.