Pet Food Nutrition: Interpreting Pet Food Ingredient Lists

Lamb, brewer’s rice, smoked salmon, mango juice, cassava root, grapefruit extract, sea urchin…

Have you ever looked at the ingredient list on a pet food label? If you have, you may have been blown away by the sheer number of possible ingredients out there, and the large differences between one type of food and the next. Manufacturers will use ingredient lists to tempt pet owners to buy their food, but it is very important to be able to read pet food ingredient labels with an educated eye.

AAFCO is the Association of American Feed Control Officials. It sets the nutritional standards for pet food in the United States, and these standards are recognized in Canada. According to AAFCO, ingredients must be listed on the label according to weight. Thus, foods high in water (like meats and vegetables) are typically listed first on the ingredient list, even though a lot of their weight is actually just water. Chicken, for example, is 70% moisture, while chicken meal is less than 10% moisture. In portions providing the exact same amount of chicken protein, whole chicken will always list higher on the ingredient list because of its water-weight.

AAFCO also provides regulations and guidelines on the definitions that can be used in pet food labels. “Meat by-product” is allowed to include organs and bones, but no intestinal contents, hair, horns, teeth or hooves. For more information on by-products, stay tuned for our next blog in the nutrition series.

Many pet foods will advertise their ingredients as “human-grade”. The term “human-grade” has no legal definition, and is actually used for marketing purposes only. Foods are labelled as either “edible” or “inedible, not for human consumption”. The only way for a pet food ingredient to be labelled as “edible” is for the meat to never leave a human food chain, to have it manufactured in a human food facility and transport it using human food trucks.

Recently a new trend is to include lots of new and exotic ingredients, including blueberries, eggs, honey, kelp and tomatoes. These ingredients sound healthy, but they may have unproven health benefits, or may be present in such small amounts that their value is minimal.

Sometimes adding new and exotic ingredients can be harmful to the environment. Initially novel protein sources, like fish, venison, rabbit and bison, were used only in hypoallergenic diets. The new trend towards including these ingredients in every-day diet not only increases the challenge of managing animals with true food-allergies, but it also increases the strain on wild populations of these alternative protein sources. In 2010, five populations of Atlantic salmon were declared endangered, one threatened, one extinct, and four others of special concern. 

With more ingredients, the degree of quality control should be increased, ensuring that each ingredient is free from contamination and that the final product adheres to the desired nutrient formulation. However, this is often not the case with many pet food companies. When choosing a pet food company, some important questions to ask include:

1)      Do they employ at least one full-time qualified nutritionist?

2)      Do they have their own manufacturing plant?

3)      Do they conduct and publish nutritional research so that continued improvements are made to their diets? (This can be tricky information to ferret out, as some companies will “publish” results internally that are not available to the general public)

4)      Do they use strict internal quality control testing and standards?

Checking out ingredients is a great way to educate yourself on what you are feeding you pet. However, try not to be swayed by marketing tactics and consider carefully what each ingredient means for your pet. Pets need nutrients, not ingredients, and it can be difficult to separate the two. Educate yourself, and be sure to ask questions.

Dr. Vanessa Tonn
Bowmanville Veterinary Clinic