'Prescription/Therapeutic' Diets - Pt 1

"Prescription/therapeutic diet" is another label that is certainly not indicative of a high quality diet or one that is necessary.

These diets represent an area of the commercial cat food industry that is very misleading and, quite frankly, a source of embarrassment for this profession.

Many of these very expensive products contain corn, wheat, and soy which have no logical place in your cat's diet. These diets are often very high in carbohydrates and, of course, all of the dry versions are water-depleted. Many of them also contain by-products as the main - and often only - source of protein.

While by-products can be very nutritious (and this really is the least of my concerns regarding these diets), they are cheaper than muscle meat so one would think that as much as these diets cost, the companies could use a more consistent source of high quality protein. (See by-products on the Commercial Food page for more details.)

Study the ingredient list for Hill's dry i/d while keeping in mind that cats are obligate carnivores.

This dry food is 29% carbohydrates on a dry matter basis and is, of course, water-depleted. The ingredients are as follows:

Chicken By-Product Meal, Brewers Rice, Corn Gluten Meal, Whole Grain Corn, Pork Fat (preserved with mixed tocopherols and citric acid), Powdered Cellulose, Dried Chicken, Chicken Liver Flavor

The base ingredients and composition mirror those of many dry foods found in pet stores and supermarkets. Also, this is a very good example of the 'ingredient splitting' rule. This rule states that ingredients have to be listed very specifically which works in the pet food manufacturers' favor. It allows the grain fractions to be broken up into smaller components which places them lower on the list since ingredients are listed by weight. However, when all of the grain fractions are added up, their contribution to the diet (including the protein content) often greatly outweighs the first ingredient.

I have asked many times on VIN (Veterinary Information Network - the 'who's who' of veterinary specialists from all over the world) just what makes this diet worthy of being called a "Prescription Diet for Feline Gastrointestinal Health" or, for that matter, what makes it an optimal diet to feed to any cat? I have never received an answer and the VIN threads have had Hill's representatives participating. My questions about the quality and composition of their prescription diets are always met with dead silence.

It is important to note that most of these diets do not have robust clinical feeding studies supporting their safety for long-term feeding or even for use in treating the various diseases they target.

On the contrary, we have plenty of evidence to show that feeding water-depleted, high carbohydrate, plant-based diets to carnivores does not honor their carnivorous make-up but, instead, promotes disease in this species.

It is also critical to understand that there is no independent agency overseeing these diets' medical claims. None. Zero. Including the FDA.

The fox is definitely guarding the henhouse and the FDA shows no interest in remedying the situation.

The FDA has 'punted' the responsibility of scrutinizing these diets for efficacy, safety, and suitability to the veterinarian but most veterinarians are very poorly educated in the area of nutrition. This field of study is not emphasized in veterinary schools and the minimal course work that is required, is often taught by people who have strong ties to the pet food industry.

These are also usually the same people who are advising general practitioners on all matters of nutrition. After recognizing this situation, you will see an obvious and very significant conflict of interest. In the end, the members of my profession allow Hill's, Purina, Iams, and Royal Canin to dictate what ends up in our patients' food bowls.

Here is an excerpt from the "Veterinarian-Prescribed Diets/OTC Options"