Hypoallergenic cat food is available from a number of pet food companies. These formulas often focus on a limited number of ingredients thought to be low allergy.
They typically use a single, low allergy protein source.
Low allergy protein sources often include lamb, duck, or venison, although sometimes other sources are used.
Interestingly, sometimes fish is used, despite some veterinarians claiming that many cats are allergic to fish.
In fact, PetMD claims that fish is "responsible for a large percentage of food allergies" in cats.
Other ingredients that are often avoided in these special diet formulas are wheat, corn, soy, and white rice.
Often instead, there will be brown rice, sweet potatoes, or possibly peas. Each formula is different, however, and nothing is written in stone.
Usually, these formulas don't contain artificial preservatives, although ironically, Hill's Prescription formula does contain BHA to preserve soybean oil.
Some of these foods may be helpful in relieving the symptoms of IBS.
Your cat may have one or all of these symptoms or not show outward symptoms that you can notice. Many cats may just have a persistent itch, or experience "hot spots" on the skin.
These symptoms, however, are not exclusive to food allergies. So, your cat may not even have a food allergy, whether or not any of the above symptoms are present. In addition, some cats may not scratch even though they itch.
Instead, they'll take to excessive grooming. Since cats groom so often anyway, you'll have to be on the lookout and determine whether or not it's excessive.
Talk to your veterinarian about allergy testing. Your vet should be able to do an allergy test so that you can better narrow down what your cat is allergic to. Then, you can choose a hypoallergenic cat food formula that better suits the allergy, as well as take other measures.
Keep in mind too that your cat could be allergic to something in one of the low allergy formulas, so just switching foods doesn't always fix the problem. At least not on the first attempt.
The above are some of the products on the market that people have had success with when dealing with cat food allergies. Again, working with your vet to have your cat tested, and then working on a change in diet is the best way to go. You may have to try more than one type of food, and working with your vet may quicken the process.
Some people have switched to homemade cat food including raw food diets and had success as well. It should be noted that this does not work in all cases either.