Dear cat-owning friends,
Allergy season is officially here—at least for me, it is! I’ve just busted out my Claritin-D and it’s getting some serious daily use. Cats manifest allergies in many ways, but one of the key ones is by “getting itchy”. Thankfully, skin allergies are not as common in cats as they are in dogs, but it’s equally frustrating to deal with (if not more so with cats because of the limitations in the number of drugs available to control the itching). Your options are pretty much limited to steroids, antihistamines (that are bitter tasting and not as effective in moderate to severe cases of allergies) or immunosuppressive medication.
When you see a cat that has been scratching excessively, it breaks your heart because you want to help them, but you don’t know how to. They can mangle themselves up so badly that they develop a skin infection.
So where do we begin with these itchy cats?
Well first off, we oftentimes want to skin scrape (if indicated) them to make sure it’s not related to underlying skin mites or parasites. This entails literally scraping the skin to the point where we see a little bit of bleeding and looking at that sample under a microscope for skin parasites. Once this is ruled out and we have determined that it’s allergies or have a high index of suspicion of it, then I usually have a talk with owners about the causes of allergies and how I work it up.
There are three main causes of skin allergies: 1. fleas 2. food hypersensitivity 3. Environmental (everything else).
01 Fleas: Yes, just because your cat is indoor doesn’t preclude them from flea allergies. I’ve seen a good handful of cats (mine included) who are strictly indoors have live fleas on them. This happens because either an owner dragged them in, they sit by a window that may be ajar, or they are exposed to it by other pets. So just because your cat is indoor only, doesn’t mean that fleas are never around. Also just because you don’t see it, does not mean fleas do not exist. That being said, the easiest way to rule it out would be to put them on a dose of a flea preventive monthly (that will be in my next topic – appropriate flea preventives for cats). You can also usually tell if it’s from fleas based on the location of any skin lesions. Most often, there will be flea dirt, scabs, or skin infection along the lower back/tail region.
02 Food: Once we have ruled out fleas via regular flea prevention and your cat is still itchy, then we consider food as the next rule out. There are a plethora of grain-free diets out there. It’s not just the grain that cats can be allergic to, though, it’s also the protein source. Ideally, what you want is either a novel protein AND carbohydrate source or consider a HYDROLYZED diet. This means that the protein and carbohydrate has been finely broken down to the point where the immune system doesn’t recognize it as foreign and therefore does not have an adverse reaction to it. Veterinary Dermatologists recommend a minimum of 8 to 10 weeks on this particular diet with no other food source such as treats or flavored chewable supplements/medications. If your cat does well, you can consider challenging them with their regular/original diet to see if they itchiness returns. Alternatively, if they respond to this diet well, then they should be on a strict hypoallergenic diet indefinitely. Please see your veterinarian for appropriate hypoallergenic diets because there are a PLETHORA of diets that claim to be hypoallergenic diet and people do their own “trial” with these over the counter diets that may not accurately rule out a true food allergy.
03 Environmental: If food and fleas have been ruled out, then the last scenario is environmental allergies. This is the most frustrating because it can literally be ANYTHING in the environment: dander, pollens, dust mites, trees, etc. This is typically where I talk to owners about seeking a veterinary dermatologist for intervention. Yes, there is such a thing! General practitioners like specialists for reasons like this—because this is ALL that they deal with. There are two types of tests you can run—one is a blood test that measures antibodies (or the body’s response) to particular allergens. Another test (performed by a dermatologist) requires sedation and a skin test. The skin test (done in humans too) involves injecting allergens within a shaved area of skin and determining what your cat is allergic to based on how raised and red the areas are (how reactive the skin is to the particular injected allergens). The goal of these tests being immunotherapy—injecting those same allergens that your cat is most allergic to back into them in low doses so their body becomes desensitized to them. The goal is not 100% resolution (though that’s ideal), but hopefully to minimize the allergies significantly or to a point where maybe a topical treatment or an occasional antihistamine is needed.
Allergies in cats are very frustrating as a whole. I don’t like having this talk with clients not only because it’s a lengthy discussion, but it’s frustrating for owners and I can sense it. It requires a lot of back and forth conversation with your veterinarian and it can be extremely costly as well. This is why it’s very important that you commit to a full workup of it. In the end, you may end up spending just as much, if not more, in the treatment of these recurrent flare ups and skin infections as it would take to try to get to the root of the problem.
In a separate post, we will talk about the different types of therapies that you can use to manage the allergies.
Thanks for reading,
Dr. Theresa Loo