Itchy Cats! (Cats Get Allergies, Too)
May 8, 2019
I’ve spent a few weeks on allergic skin disease in dogs, now let’s give some attention to our cats. Cats can have allergic skin disease, too, but because they are mysterious creatures they have to do things their own way… and we don’t always understand their way very well. Their symptoms tend to be different than dogs’ and can be subtle and inconsistent. Because there hasn’t been as much research into allergic skin disease in cats as there has been in people and dogs, we don’t know as much about them and the exact mechanisms of allergic skin disease are not completely defined or understood. So this week I’ll talk a bit about what we know and don’t know about it all and how we can help our itchy cats.
Unlike dogs, defects in the normal skin barrier have not been definitively shown to be present in cats but this is a topic that is currently under investigation. The exact chemical pathways also aren’t completely understood; for example, cats have and make IL-31 but its exact role in allergic skin disease hasn’t been clearly defined. More is known about allergic bronchitis and asthma in cats, and there is some evidence that the pathways of allergic skin disease are similar but again, this is under investigation.
So what DO we know? Anything?
We know that cats are most commonly affected on the face, head and neck, legs, rump, belly, or ear flaps. They often have what is called a “miliary” pattern – a scattered distribution without a clear arrangement. They frequently either lick or chew and pull out their hair when they are itchy rather than obviously scratching. Their skin may not look generally red, but they may have patches of redness or sore, oozy patches. A very focal skin eruption called eosinophilic plaque (aka eosinophilic syndrome) may be associated with a general environmental allergy.
Unfortunately, symptoms are not as easily tied to allergic skin disease in cats as in dogs because they can have so many other causes. For example, pulling out hair is a common stress/anxiety displacement behavior in cats. In general, we need to rule out other causes of itchy skin such as fleas, contact irritants such as dyes or fragrances in laundry or cleaning products and also rule out behavioral hair pulling due to stress and anxiety before arriving at a diagnosis of allergic skin disease.
One other causes have been ruled out and we suspect environmental allergies, what options do we have for treatment? Some of them are similar to options for dogs discussed in this post, while others can’t be used. Please read through that post because rather than repeat all of the information, here I will go through them more briefly with an emphasis on whether we can use them and any considerations specifically for cats.
Cats do not get secondary skin infections as commonly as dogs, but when they are present it very important to treat them appropriately with antibiotics.
Non drug options are the same for cats as dogs. However, there are a few differences:
- Bathing is thought to be helpful for cats even though it isn’t yet known for sure that a defective skin barrier is at play. However, bathing a cat can be like handling a wet and soapy razorblade tornado, so this may not be practical. It is not important enough for you to ever put yourself at risk of being scratched or bitten, just skip it if your cat isn’t a water lover. An alternative that will work for most cats is to periodically wipe over the entire body with a damp washcloth.
- Omega 3 fatty acid supplements can help reduce inflammation and allow the skin to repair itself. My favorite brand for cats is Welactin.
- Hyposensitization (“allergy shots”) is an option for cats. Interpreting skin allergy testing results in cats can be more difficult in cats than dogs and is definitely a job for a veterinary dermatologist. Like dogs, this may not completely eliminate the need for drugs but should reduce it.
Antihistamines are an option but like dogs, they are not commonly effective.
Cortisone-like steroids (prednisolone) are usually extremely effective but as with dogs, there can be serious side effects associated with long term use. In cats particularly, we can (very rarely) see something called steroid-induced congestive heart failure in cats that have known or unknown pre-existing heart disease. And although steroids do not cause diabetes, they can push a cat in a pre-diabetic state into clinical diabetes which may or may not reverse once the steroid is stopped.
Cyclosporine (Atopica for Cats) is a better long term choice for cats. It is usually well tolerated in cats but can sometimes cause GI upset. The product for cats comes as an oral liquid.
Atopica is not approved for use in cats, but it is being used in some instances (off label) in cats when other medications are not effective. We recommend that this should be done only under the supervision of a veterinary dermatologist until more is known about this medication in cats.
Cytopoint can not be used safely in cats. It is a biologic product that has been engineered specifically from and for dogs and a cat’s immune system would recognize it as foreign. At best, it would do nothing and at worst, it could trigger a severe allergic reaction.
The bottom line is that while itchy cats are not just small itchy dogs, we still have many options to help them. It can be more of a process to arrive at a diagnosis, but once we get there we can help itchy cats!
As always, if you have any questions please feel free to call or email the clinic.
Karen Christopherson DVM CVA
