Another animal food contaminant that can cause illness and injury to animals and humans is aflatoxin. Aflatoxins are naturally occurring mycotoxins that are produced by many species of the fungus Aspergillus on certain agricultural commodities. Since their discovery in the early 1960's, aflatoxins have been shown to be toxic to animals and humans. Aflatoxins have also been shown to be carcinogenic to laboratory test animals. After consumption, aflatoxins are metabolized by the liver to a reactive intermediate and eliminated as aflatoxin M1 in milk or as aflatoxicol in urine. High level aflatoxin exposure produces acute damage and cirrhosis of the liver as well as cancer of the liver. It appears that no animal species, including humans, is immune to the acute toxic effects of aflatoxins. In 2005, a pet food company in South Carolina recalled dog food that was contaminated with aflatoxin (Ref. 23). The Agency received reports from 4 states of illness in over 40 dogs, including 23 deaths, associated with the consumption of the contaminated pet food. In addition, the company's contaminated pet food was exported to at least 29 foreign countries. The source of this contamination was traced to local corn, which had been contaminated with aflatoxin before entering the pet food facility.
Microbial contamination of animal food is also a high concern for the Agency, not only for animals consuming the contaminated food, but also for humans that handle that contaminated animal food. In 2007, FDA identified S. Schwarzengrund, a rare serotype of Salmonella associated with human illness, in a pet food. The Center for Disease Control and Prevention (CDC) traced this rare strain of Salmonella to a pet food manufacturing facility located in Pennsylvania. Analytical tests conducted by FDA confirmed S. Schwarzengrund at the Pennsylvania facility. A recall was issued for two brands of dry dog food and the manufacturing facility ceased operations for 5 months for cleaning and disinfecting. Despite the facility's efforts, additional S. Schwarzengrund illnesses in humans were reported to CDC. After further investigations by FDA, the pet food manufacturing facility issued a nationwide voluntary recall of all dry dog and cat food products produced at the facility over a 5 month period. This recall involved approximately 23,109 tons of dry pet foods, representing 105 brands. While no pets were reported sick, 79 people in 21 states were reported ill due to the handling of pet food contaminated with this Salmonella strain (Ref. 24).
In 2010, the CDC notified FDA of an outbreak of salmonellosis (Salmonella infection) in people in the United Kingdom and the United States. News reports from the United Kingdom indicated over 200 people had become ill, all from the same strain of Salmonella (Ref. 25). UK officials had determined patients in the United Kingdom had been exposed to frozen rodents used as animal food for reptiles and determined these frozen rodents were contaminated with the same strain of Salmonella that was causing the human illness outbreak. U.K. officials traced the origin of these contaminated frozen rodents to a supplier in the United States. UK officials then contacted the CDC. The CDC determined from illness reports that 34 patients in 17 states in the United States were diagnosed with salmonellosis associated with the same strain of Salmonella as the patients in the United Kingdom and of that found in the frozen rodents (Ref. 26). FDA inspected the facility producing the frozen rodents and isolated the same strain of Salmonella from frozen rodent products sampled at the facility. The facility had distributed frozen rodents as animal food worldwide.