I never really wanted to be an expert in pet food safety, but as soon as I started as a veterinary toxicologist in the state of New York, we had a disaster. It was 2005, around the winter holidays, and dogs were getting sick, really sick. Many died, bleeding into their lungs and intestines. The pathology resident wanted to diagnose either leptospirosis or “a toxin.” I was rooting for leptospirosis, but it sure looked like what I’d read about aflatoxin, a mold byproduct, which is what it was. It hit the national news. There was so much morbidity and mortality in New York that the veterinary college had to hire therapists to get the students through the holidays and into the new year. The affected product was identified and recalled, and the problem subsided.
About a year later, a new problem emerged. It was early 2007, and a veterinarian for a colony of cats reported an uptick in deaths from renal failure. OK, so renal failure in cats doesn’t usually raise many eyebrows, but what was unusual was the number of cats—and dogs—being reported with renal failure. Honestly, I was again rooting for leptospirosis, but, again, it wasn’t. We had no idea what we were dealing with for weeks, but eventually, we figured out a polymerizing plastic progenitor called “melamine” with a high nitrogen content was the culprit. It was being added to a wheat flour ingredient, fraudulently labeled “gluten meal,” that was used by multiple pet food manufacturers. Gluten is a source of protein. Protein in food is measured by determining the total nitrogen concentration and then calculating the protein content. This assumes that the nitrogen is actually from protein, but in this case it was from the melamine. Melamine contamination was complicated by interactions with other chemicals in the adulterated products. The resulting recall was the largest pet food recall in United States history, affecting multiple large brands and untold numbers of cats and dogs. It was also a sentinel event: the following year, children in China were sickened by renal failure after drinking infant formula. I heard the news as I was traveling to a conference, where I ran into a senior official from the US Food and Drug Administration (FDA). So, I asked him if there was any chance . . . and yes, he said, the infant formula was loaded with melamine. It took 24 hours from the first reports until melamine was detected in baby formula; veterinarians had already alerted the world to the potential problem. Approximately 300,000 children were reported to be affected, but because of the knowledge accumulated by veterinarians, prompt actions resulted in recovery for the vast majority. Alas, 6 babies perished. Still, you can imagine how proud I was that our efforts to help cats and dogs had such far-reaching public health implications.
That is why I have learned about pet food safety, and a little bit about public health. We don’t live in a perfect world, accidents happen, and there will be more pet food recalls in the future. Lax food safety protocols invite trouble. Add to that the fact that our companion animals are more susceptible to food-related poisonings than most people because of the way they consume food. We value variety in our own diets, which helps us meet our own nutritional needs. Pet foods, though, are balanced; pets can eat the same food, from the same bag or product lot, for days or weeks on end. If there’s a contaminant, they are likely to be exposed for a long time. Most pet food recalls are caused by natural contaminants, like microbes, microbial toxins, and formulation errors (either too much ingredient, too little, or the wrong ingredient entirely). Sometimes, known toxic contaminants cause unexpected problems: the mycotoxin T-2 appears to have caused pancytopenia in cats in Europe last year, and dog food was contaminated by the plant toxin indospicine in Australia. Melamine was a red flag: we learned that fraud happens, and novel contaminants are difficult to identify. Also, melamine taught us that pet food contaminants can foreshadow public health events.
So, how do we protect pets? There are multiple layers of vigilance. We rely first on the pet food companies to have good quality control, then on consumers and veterinarians who monitor animal health on a day-to-day basis, and then on regulatory agencies to remediate problems that come up.
Most large pet food companies have stringent manufacturing safety protocols based on Hazard Analysis and Critical Control Points (HACCP). The basic idea is that you figure out where contamination can happen (for example, rodents getting into the building carrying pathogens) and the best way to prevent it from happening (keeping buildings secure from pests and pasteurizing the final product to kill pathogens). You continually review your program, solve problems, and anticipate new problems. Human error is a given, but HACCP works well most of the time. As I write this, there are 1,610 current FDA recalls, of which only 113 are related to veterinary and pet products. But, as we already learned, you can’t anticipate every possible problem.
Those of us who work with and live with animals are the next level: veterinarians and pet owners. Many pet food recalls I’ve worked on have started with an extremely astute veterinarian who asked “why am I suddenly seeing this problem so often?” An excellent medical history and physical examination, and, in the worst-case-scenario, postmortem examination, are essential for documenting a pet food problem. Product packaging and information for product identification purposes (name, lot number, expiration date) are a necessity when filing complaints to the manufacturer and the FDA. The manufacturer’s contact information should be present on packaging, and the FDA can be contacted through the pet food complaint website: http://www.fda.gov/cvm/petfoods.htm.
The FDA has regulatory authority for pet foods. They monitor complaints and determine if there is a sudden uptick in problems associated with a product. When they detect a problem, a case definition is formed: a pattern of clinical signs typical of the problem. Based on this case definition, the FDA can go back to veterinarians and scientists to determine the most likely suspect contaminant for which to test. If a contaminant is found, the FDA can then request that the contaminated product be recalled. It has been my experience that most manufacturers are willing to work with government regulators; most of the pet food company people I’ve worked with have been caring and concerned about their customers and companion animals.
Pet food safety has become part of my life as a veterinary toxicologist. I’m hoping that what I’ve learned will be helpful in keeping our animals healthy and protecting public health.