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Your pet itches and she is causing severe skin problems due to scratching. You suspect food is the cause. You go to the big-box pet store and peruse the brands that claim to “improve skin and coat quality” on the container label. This may be wrong for two reasons.

The first is that food is not a major cause of itching and skin disease in pets. Second is that a recent study of foods claiming to improve skin and coat quality do not offer advantages that might achieve that purpose. Let me explain.

Cutaneous Adverse Reactions to Food (CARF)

The leading cause of skin disease is bugs—fleas in particular. The second leading cause is environmental proteins. These can be tree, plant, or grass pollens, fungal spores, or dust from dead mites and other insects and microorganisms. Food is the last possibility.

Two recently published scientific surveys suggest that only 7.6-12 percent of allergic skin reactions can be attributed to food. Anecdotal accounts from some veterinary dermatologists indicate the possibility of skin allergic reactions to food as high as 25 percent.

The point of all of this information is that pet owners suspect food as the primary cause of allergic skin reactions, or cutaneous adverse reactions to food (CARF), when the reality is that the actual incidence is much lower.

Why do owners react this way? Incorrect internet information claiming the importance of food in allergic reactions is overwhelmingly available. Changing food brands is much cheaper than a veterinary exam. Owners also know that allergy testing for food is very inaccurate and that their veterinarians may not be very knowledgeable about nutrition.

So, why wouldn’t pet owners experiment without professional advice? A recent study suggests why owner experimentation may not be rewarding for improving skin and coat quality in their pets.

Study Findings

A group of veterinary nutritionists, including a colleague of mine, from Tufts University School of Veterinary Medicine, examined 24 over-the-counter (OTC) food brands that claim to help promote “skin and coat quality.” They examined the ingredients to determine if they would indeed help with skin disease caused by CARFs. The findings were quite interesting.

Novel ingredients — Veterinary dermatologist all agree that determining or diagnosing a CARF requires that a pet be fed proteins from meat or carbohydrates that it has unlikely experienced before; in other words, a novel protein. The list of most common allergenic foods (not novel) according to veterinary dermatologists is:

  1. Beef
  2. Dairy
  3. Wheat
  4. Egg
  5. Chicken

Yet the study found that chicken and egg proteins were the most common ingredients found in pet foods claiming to improve skin and coat quality. The foods also included rice, potato, and oats, which are now found so commonly in pet foods that they have lost any novel status as carbohydrate sources.

Interestingly, the researchers found that most manufacturers of brands promoting skin and coat quality emphasized the lack of corn in their formulas, despite the fact that corn has not been proven by veterinary dermatologists to be a major allergen containing food.

Essential Fats — Proper amounts of dietary omega-3 and omega-6 fatty acids are necessary for optimum skin and coat quality. Yet less than a third of the food makers could provide the researchers with the exact amounts of omega-3 and omega-6 in their formulas.

Necessary Calories — Pet food is formulated so that all of the necessary daily nutrients are met if the pet consumes the proper amount of calories in the food formulation. 12.5 percent of the foods purporting skin health failed to meet the AAFCO standards for the caloric needs of pets.

This research and my other posts detailing the hazards of hypoallergenic diets should give you pause about commercial pet food as a viable alternative for your dog’s health. You might want to consider instead a quality homemade pet food program.

Dr. Ken Tudor 

Image: Jaromir Chalabala / Shutterstock

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