About the only thing dog-food manufacturers can agree on is that no one can agree on the optimal ingredients – or ratios of them – that belong in Molly’s dinner bowl.
For their part, manufacturers of more natural foods have tried to minimize the use of chemicals and synthetic ingredients. From anti-caking and anti-gelling agents to flavor enhancers and texturizers, dog food has plenty of them.
Here are 10 ingredients sometimes found in “regular” dog food that likely won’t be present in their “natural” counterparts:
Butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT): There’s no getting around it – dry dog food requires preservatives to prevent spoiling. Natural brands tend to use healthier choices such as vitamin C (ascorbate) and vitamin E (mixed tocopherols), though they provide a much shorter shelf life. By contrast, synthetic preservatives BHA and BHT can extend shelf life to as long as one year. There is concern, however, about studies that have suggested they are carcinogenic.
Ethoxyquin: Another chemically synthesized preservative whose long-term safety in dogs has not been studied. Some reports have noted impaired liver and kidney function. Though the U.S. Food and Drug Administration concluded the additive does not pose a health threat, in 1997 the government agency reduced the amount of ethoxyquin permitted in dog food.
Propylene glycol: This clear, colorless liquid is used in some semi-moist foods to prevent them from drying out. It may be toxic if consumed in large amounts, causing central nervous system impairment and changes in kidney function. Propylene glycol is also the basis for less-toxic antifreeze used in dairies and breweries.
Propyl gallate: This fine white powder is an antioxidant that helps keep the fats and oils in a food from spoiling. In humans, it can cause stomach and skin irritation.
Coloring agents (such as Red 40 and Yellow 5): Manufacturers use these and other “food, drug, or cosmetic colors” to enhance the appearance of dog foods. More health-conscious brands seek out natural ingredients, such as carrots, for color-enhancement.
Phosphoric acid: This clear liquid is sometimes used as an emulsifier and flavoring agent. It also inhibits discoloration. But concentrated amounts can irritate dogs' skin and mucous membranes.
Sorbitol: A popular synthetic sugar substitute, sorbitol is used as a flavoring agent. If eaten in large amounts, it can cause diarrhea and intestinal upset in dogs.
Dl-alpha tocopheryl acetate: Vitamin E is commonly used as a preservative in natural dog foods. This synthetic form of the vitamin is not as readily absorbed by the body as its natural counterpart (mixed tocopherols).
Menadione sodium bisulfate vitamin K3: This synthetic version of vitamin K is sometimes also listed as menadione dimethyl-pyrimidinol bisulfate, menadione dimethyl-pyrimidinol bisulfite, and several other variations. Critics contend it is an unnecessary ingredient in dog food, and reports indicate it can irritate mucous membranes, respiratory passages, and the skin.
Denise Flaim is a DOG FANCY contributing editor.