Pet Food Nutrition: By-products

Let’s talk about that nasty “B” word when it comes to pet nutrition: “By-products”.

Unfortunately by-products have become the dirty word in pet food manufacture, and part of the problem is that many people do not understand what is included in by-products. Legally, by-products can only include internal organs. They do not include hooves, feces or roadkill, as is commonly assumed by consumers and pet owners.

AAFCO, the Association of Food Control Officials, defines meat by-products as “the non-rendered, clean parts, other than meat, derived from slaughtered mammals. It includes, but is not limited to, lungs, spleen, kidneys, brain, livers, blood, bone and stomachs and intestines freed of their contents. It does not include hair, horns, teeth and hooves.”

For people in North America, some of these ingredients may seem strange, as we are generally more accustomed to eating the muscle portion of the animal only. However, there are many regions and cultures who appreciate these different parts as delicacies.

• Sweetbreads – thymus
• Rocky Mountain oysters – testicles
• Haggis – Sheep heart, liver, lungs and stomach
• Steak and kidney pie

Besides many of these products being higher in essential nutrients than muscle meat, feeding by-products can help the environment and reduce waste, as it allows the entire rendered animal to be put to good use, rather than discarding by-products that would otherwise be unused in most human circumstances.

• Brain – provides DHA, an anti-inflammatory fatty acid important in neurological development
• Blood – provides iron, and essential mineral, and protein, which contributes to daily requirements of protein
• Bones – source of essential minerals that support strong bones and teeth
• Connective Tissues – source of chondroitin, which supports joint health
• Heart – provides taurine and L-carnitine, both which support heart health (taurine is essential for cats)
• Liver – provides iron, B Vitamins and Vitamin A, which supports multiple systems including nervous system, growth, vision, etc.

Also, did you know that many dog treats are actually by-products? Lung, liver, tendons and pig-ears are very popular dog treats. Bully sticks, fed by 26% of consumers who said that they avoided feeding their dogs by-products, are actually bull penises.

Providing that a pet food is made from a reputable manufacturer who adheres to stringent quality control and employs full-time, qualified nutritionists, feeding a diet that contains by-products can be a safe and nutritional choice. 

Dr. Vanessa Tonn

Bowmanville Veterinary Clinic