Diagnostic dilemma: "I know the pet food was responsible" (Proceedings)
When a pet exhibits signs of gastrointestinal disease, the owner often concludes that its food must be the culprit. Pet owners are particularly sensitized to the issue of pet food safety as a consequence of the large pet food recall of 2007 in which imported feed commodities intentionally contaminated with melamine, cyanuric acid, ammeline and ammelide were incorporated into pet foods.
In the past, when pets relied on table scraps, carrion, garbage, and improperly cooked pet foods for sustenance, this conclusion was reasonable. Today, foodborne disease in household pets is rare. The 1990 annual report of the American Association of Poison Control Centers (AAPCC) indicated that of the 41,854 cases of dog and cat poisonings reported, foodborne illnesses accounted for only 1.7% of the total. This phenomenon can be attributed to the fact that most pets in developed countries depend on processed commercial pet foods for their daily diet, instead of fresh food or table scraps. Present-day commercial pet foods are much safer than those in the past because of modem manufacturing methods and a high degree of governmental regulation. There is an incentive for pet food manufactures to provide a safe and nutritious product since procedural breakdowns or accidental contamination during the production or storage of a pet food product can have a catastrophic effect on company profits and reputation and even the future viability of a company.
Modem pet foods are not composed of a single ingredient but are formulated from multiple ingredients, including grains, meats, meat by-products, vegetables, eggs, dairy products, fish, and other added nutrients. The use of many and varied ingredients tends to dilute any contamination in a particular commodity or ingredient. Commercial pet food manufacturers commonly use manufacturing techniques such as extrusion for dry foods and cooking in a commercial retort for canned foods to produce temperatures high enough to destroy most pathogens and heat-labile toxins. Improved packaging materials and a better knowledge of proper warehousing also help protect raw materials and finished products from moist conditions and possible contamination during storage. Furthermore, manufacturers use sensitive analytical techniques to verify that ingredients and final products are high quality and free from contaminantsPet foods and individual pet food ingredients that are shipped across state or international boundaries are regulated by the U.S. Food and Drug Administration (FDA) under the authority of the Federal Food, Drug and Cosmetic Act (FFDCA). Section 402 of the Act states that foods, including pet foods, shall be considered adulterated when they contain an added substance (e.g., bacteria, mycotoxins, drugs, pesticides, metals) that may render the food injurious to health. The Act further empowers the Secretary of Health and Human Services to promulgate regulations and tolerances that limit the quantity of these unintentional added substances. The FDA monitors pet food and individual pet food ingredients for pesticides, mycotoxins, and heavy metals as part of its Feed Contaminants Program. Pesticide tolerances for food ingredients and food products are unique in that they are not set by the FDA but instead fall under the jurisdiction of the U.S. Environmental Protection Agency (EPA) under the authority of the FFDCA and the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA). They are developed by combining the results of crop and animal field trials with laboratory animal toxicity data. The EPA establishes and publishes pesticide tolerances for the various plant and animal commodities in 40 CFR 180. The U.S. Department of Agriculture (USDA) and the FDA jointly enforce the EPA pesticide tolerances. For contaminants not covered by a specific tolerance level, the FDA may choose to issue either an action or an advisory level. Both are considered maximal allowable levels; however, an action level is generally supported by more definitive safety data than is an advisory level. Action and advisory levels constitute nonbinding FDA guidance that the agency uses in exercising enforcement discretion when considering product adulteration. There may be circumstances that warrant enforcement below an action or advisory level or in which enforcement is not warranted even though an action or advisory level has been exceeded. For contaminants not covered by any of previously discussed limits (tolerance, action, or advisory level), the maximum remains theoretically at zero. However, the sensitivity of present-day analytical methods has progressed to the point that minuscule amounts can now be detected. Fortunately, the FDA is able to exercise discretionary power when a contaminant is detected at a low level not considered to be a safety concern. Finally, intrastate pet foods are less subject to federal scrutiny and fall under the authority of local and state officials.