Allergies in Cats
Cats are commonly affected by allergies. An allergy occurs when a cat's immune system overacts to foreign substances or particles (called allergens). This overactive immune system can cause any of the following allergy symptoms in cats:
- Skin itchiness causing scratching and rubbing
- Sneezing, coughing or wheezing
- Vomiting, diarrhea, gas or bloating
Types of Cat Allergies
There are four types of allergies that affect cats. These include:
- Flea allergies
- Food allergies
- Airborne allergies (atopy)
- Contact allergies
As a cat owner, it is important to educate yourself about the unique signs associated with each type of allergy. If your cat exhibits any of these allergy symptoms, see your veterinarian to discuss treatment options to give your cat relief from allergies.
Flea allergy is probably the most common allergy in cats. A normal cat will experience minor irritation and itching from a flea bite. A cat with flea allergy, however, will have a severe reaction to a single flea—they will often bite and break the skin and even remove large patches of their own hair. There will often be open sores or small scabs present on their skin. The most common areas of the body affected by flea allergy are the rump, head and neck.
Treatment of flea allergy includes strict flea control. Fleas can be very difficult to kill but with modern flea medications and home treatment options, your veterinarian can help you rid your home and cat of these pests.
Cats are not born with food allergies. It is actually more common that they develop allergies to a food they have eaten for many years. Food allergy can strike at any age and allergies usually develop to the protein component of the food. Allergies to beef, pork, chicken, and turkey are the most common. Cat food allergy can produce severe skin itchiness, gastrointestinal upset or respiratory allergy symptoms. Food allergy testing is recommended when allergy symptoms have been present for several months, if a cat has a poor response to steroids, or when a very young cat itches without other apparent causes of allergy.
Testing involves a "diet trial" selected and monitored by your veterinarian. During a "diet trial", a commercial or home-made hypoallergenic diet is fed exclusively for 8 to 12 weeks. During this time, your cat must ONLY eat the prescribed food—no table food, scraps, treats, vitamins or chewable medications can be given during a diet trial. If a positive response is seen after this trial, your veterinarian will advise you on how to proceed. Treatment is easy—just feed a diet without the allergen!
Airborne Allergy (Atopy)
Allergies to particles your cat inhales is called atopy. Common allergens include tree pollens (cedar, ash, oak, etc), grass pollens (bermuda, etc), weed pollens (ragweed, goldenrods, etc), molds, mildew and house dust mites. Many of these allergies occur seasonally, such as ragweed and grass pollens. Others, such as molds, mildew and house dust mites are year-round problems. When humans inhale these allergens they usually develop respiratory signs ("hayfever"). When cats inhale these allergens they develop severe itching of the entire body.
One of the most important treatments for atopy is to minimize your cat's exposure to things he is allergic to. For example, if a cat is allergic to pollen, he should be kept inside with the windows closed when pollen counts are high or the grass is being mowed. Air filters also help remove many airborne allergens to keep the home environment clean.
Other treatment options are chosen based on the severity of your cat's allergy symptoms and the length of his allergy season. For example, if your cat itches a few weeks once or twice a year, your veterinarian may recommend shampoos and anti-inflammatory medications to help alleviate his allergy symptoms. However, if your cat itches year-round, or so severely that he has open sores, your veterinarian may recommend skin testing and allergy shots (see below).
This is the least common type of allergy and is caused by something your cat comes in contact with, such as carpet, bedding (especially wool), or detergents. If your cat is allergic to such substances, there will be skin irritation and itching at the points of contact (elbows, bottom of the feet, belly, etc). Treatment involves identifying and removing the allergen.
Diagnosis of Allergies
If you suspect your cat has allergies, you should see your veterinarian. Veterinarians will usually make a preliminary diagnosis and treatment plan based on the following information:
- Season(s) of the year when your cat has the most allergy symptoms
- What body locations are the most itchy
- Response of the itch to medications (e.g. shampoos, antihistamines, steroids, etc)
If the initial treatment does not give your cat relief, your veterinarian may recommend more specific "allergy testing". Allergy testing is done by either taking a blood test or performing intradermal skin testing. The blood tests are reasonably reliable for detecting airborne allergies but not as good for food or contact allergies. Skin testing is considered more accurate and involves shaving a patch of hair on your cat's side and then injecting small amounts of allergens under the skin. A positive test is diagnosed if there is a reddening or welting of the skin after injection. Those offending allergens can be mixed together by a laboratory and very small injections given weekly at home over several months to help your cat become less sensitive to them. Up to 75% of cats that receive allergy shots will have improvement in their signs—but it can take several months (up to one year) to see the full effect.
Treatment of Allergies
In addition to specific treatments listed above for each allergy type, your veterinarian may recommend the following treatments to give your allergic cat relief during his most itchy times:
- Shampoo -- frequent bathing with a natural shampoo removes pollens, debris and other allergens from the coat that could be absorbed through the skin. Your veterinarian may prescribe a medicated shampoo or conditioner that contains anti-inflammatory ingredients if your cat needs additional relief.
- Anti-inflammatory medications -- steroids, antihistamines or cyclosporine may be prescribed as they dramatically block the allergic reaction in most cases. These medications create almost immediate relief from skin irritation and severe itching associated with most types of allergy.
- Antibiotics -- often the itch of allergy is made worse by bacterial or yeast skin infections. Your veterinarian may recommend the use of oral antibiotics or anti-yeast medications to treat these infections.
Additional things you can do at home to minimize the itchiness of your allergic cat:
- Try to minimize the exposure of your cat to the suspected allergens.
- Feed your cat a high quality natural cat food with proper pet supplements to ensure they have no dietary deficiencies.
- Give your cat a pet supplement with fatty acids to provide beneficial anti-inflammatory properties and improve the quality of their skin and coat.
- Use stainless steel or glass feeding dishes and clean them regularly.
- Brush your cat's hair coat regularly to distribute the natural oils and prevent mats that can further irritate itchy skin.
- Apply a natural ointment in areas where the skin is broken or in "hot spots."
- Use flea preventative regularly as allergic cats tend to be even more sensitive than normal cats to flea or insect bites. A natural herbal dip is a gentle alternative to harsh chemicals.
- Wash your cats bedding with hypoallergenic detergent in very hot water.
It can be miserable to watch your cat suffer with allergy symptoms. Using natural pet products and working closely with your veterinarian will ensure your cat will be as comfortable as possible.
Donna Spector, DVM, DACVIM, ,is a renowned, board-certified Veterinary Internal Medicine Specialist who has practiced at the Animal Medical Center in New York City and other leading institutions. She is an active member of the American Veterinary Medical Association (AVMA) and the American Holistic Veterinary Medical Association. Dr. Donna has written and lectured extensively on topics including nutrition, diabetes, gastrointestinal disorders, kidney failure and respiratory disease. She is widely recognized for her role as consulting veterinarian to HALO, Purely for Pets, her TV appearances with Ellen DeGeneres and her widely-quoted pet health advice in print and on radio. Dr. Donna performs medical, nutrition and weight loss consultations for dogs and cats through her web-based veterinary consulting service, www.SpectorDVM.com.