Studies have shown that food allergies account for the third most common type of feline allergy. Although itchy, irritating skin problems are the most common signs of this allergy, an estimated 10 percent to 15 percent of affected cats also exhibit gastrointestinal signs, such as vomiting and diarrhea.
The itching that typically signals the presence of a food allergy is caused in response to the presence of an allergen, a substance to which the animal’s system is abnormally sensitive. The itching tends to be mainly in the head and neck area.
The constant scratching may cause secondary skin wounds and result in a vulnerability to severe bacterial infection. In addition, gastrointestinal problems stemming from a food allergy may have far-reaching systemic implications, including food avoidance that can result in health-compromising weight loss.
The most visible signs of a food allergy—the persistent scratching, the emergence of skin lesions, loss of hair, and a general deterioration of the coat—do not develop overnight. Instead, they tend to become evident and intensify over extended periods of time—months or even longer—as the animal’s immune system gradually mounts a defence against certain protein and carbohydrates that maybe present in the wet or dry cat food. There is no particular explanation as to why this allergy develops.
A cat of any age can be affected, and it can occur in a cat that has been on the same diet for years.
If a food allergy is suspected, the specific allergen must be identified and removed from the animal’s diet.
The best way to identify the allergen is by process of elimination.
The simplest way to do this is to introduce what is called a “novel” protein diet. The novel diet must contain a protein source to which the affected cat has not been previously exposed, such as rabbit, venison or kangaroo meat etc. If a cat consumes nothing but a novel protein diet and water for a period of at least eight to 10 weeks, it is likely that the allergic signs will gradually disappear. In that case, the owner can assume that the cat was allergic to the protein in the previous diet.
Alternatively, it may be that your cat is allergic to additives in its diet, rather than the protein source itself. Therefore, it is always a good idea to have a good look at the ingredients in the food that you are feeding. If your cat is not eating a raw diet, the transition to raw will normally cure the allergen, as it is a more natural, species appropriate diet. Also, most cats have some degree of intolerance to the high amount of carbohydrates in many of the commercial diets available, including most if not all, prescription diets.
Please remember that if there is any evidence of medical conditions in your cat, or if you are concerned in any way, you should seek the advice of a veterinarian.