Cat Food Allergies

"Cat food allergies represent 10% of all allergies a cat can suffer from. It is estimated that approximately 1–5 ingredients of a cat’s food can act as an allergen. Skin pruritus (severe itching often on undamaged skin) and itching, alopecia (hair loss), aggressiveness and skin lesions are the primary food allergy symptoms. Clinically it is hard to differentiate feline food allergies from other seasonal allergies, although the year round presence of allergy can suggest cat food allergy. The most suitable approach to diagnose pet food allergy is a “Strict Food Elimination Diet”, in which food ingredients are eliminated individually to diagnose the component of food that is causing the allergic reaction. Food adjustments and elimination of the causative ingredient is the only effective option to treat pet food allergies. Steroidal drugs are effective, but the effectiveness of the medication declines with repeated administration."

Causes of Cat Food Allergies:

Specific ingredients within cat food trigger an allergic reaction due to hypersensitivity of the cat’s immune system. Cats of any age, breed, and sex can be hypersensitive and can suffer food allergies. It is considered that the common formulation of commercial cat food contains at least 1–5 ingredients which can act as food allergens. The goal is to discover which ingredient is causing the allergic reaction.

Many ingredients that are found in commercial cat foods can act as allergens such as beef, seafood (Fish), dairy products, chicken and wheat gluten. Most of these ingredients hyper sensitize the complementary proteins of the immune system, resulting in an  allergic reaction at the base of the hair follicles on the skin.

Symptoms of Cat Food Allergy:

Feline food allergies can be most often characterized by skin problems. Cats can experience a generalized distribution of itching, pruritus or irritation on the skin. Alopecia (hair loss) is usually focal (in a small area) and sporadically noticed, especially at the neck, ear tips and legs. In severe allergic reactions, or in advanced stages of cat food allergies, dermatitis and the development of a granuloma (A mass of inflammation) complex on the skin particularly at site of alopecia is common.

Diagnosis of Cat Food Allergies:

It is hard to differentiate cat food allergy from other types of feline allergy, especially seasonal allergies (also called cat atopic allergies). Some factors like year round allergy problems can suggest a food allergy problem.

It is also required that feline food allergies be differentiated from food intolerance, it can be done by symptoms of vomiting and diarrhea along with skin problems; which only occur in the case of food intolerance.

Dietary restriction and using an ingredient elimination technique is the only effective way to diagnose food allergies in cats; ingredients are either restricted or reduced in the food with a change in allergic condition noted after each change. It is a laborious technique, but it is required in order to treat pet food allergies effectively.

Blood and serological tests for antigen–antibody relation and for a complementary response to certain proteins can be helpful in making a diagnosis.

Treatment of Cat Food Allergies:

Dietary adjustments are usually required to effectively treat pet food allergies. It is essential that the diet is changed. Either a quantity of a specific ingredient needs to be reduced to a non–allergic level or it needs to be eliminated.

Elimination diets are also available commercially such as Hill's Prescription Diet d/d, and should be used continuously for at least 3 months. Food adjustments in cats are usually a very difficult task, both habitually and physiologically.

The response time for elimination diets is usually 1–9 weeks, with the first signs being a reduction of pruritus or itching. When improvement is noted, a dietary adjustment is made.

Home made cat foods are usually the best option in the case of allergies, as it is much easier to eliminate or add specific ingredients. The only drawback associated with homemade foods is the need to maintain the correct nutritional balance, which is hard to maintain.

Steroids can be used as an alternative, but this type of treatment is never a durable or recommended option. Similarly, fatty acids and antihistamines can be used, but are not recommended, as the efficacy of these drugs reduces with time, usually after 3 months of continuous administration. The reduction in effectiveness is 50% and at that point the medication cannot be used anymore as an effective therapeutic agent.

A homeopathic remedy might providing lasting relief from itch caused by food allergy and can help to restore skin condition.  A product such as Allergy Itch Ease is made specifically for this purpose.


The Merck/Merial Manual for Pet Health