Deadly Aflatoxin: Is your pet food safe?
By Hyperflite Staff

Aflatoxin is certainly not a household word. But if you are a pet owner, it is one that you should resolve to become familiar with. Your pet’s health may be at stake. O.K., here’s the science. Aflatoxins are mycotoxins that, in addition to being extremely toxic, are also carcinogenic and immunosuppressive in nature. Alflatoxins may cause injury or disease even when ingested in small amounts. Aflatoxins are produced as secondary metabolites by many species of Aspergillus fungi (most notably Aspergillus flavus and Aspergillus parasiticus). Many agricultural crops including corn, rice, wheat, nuts, soybeans, sunflowers and even milk, are vulnerable to attack by the fungi that produce aflatoxin.

The injurious nature of aflatoxin became known in 1960 when it was discovered that the toxin, present in peanut meal, was responsible for the death of more than 100,000 turkeys in Great Britain.

The Aspergillus fungi that produce Aflatoxins are very common in nature and are frequently found in crops that have been exposed to high humidity for long periods or that have been damaged by drought.

The native habitat of Aspergillus fungi is in soil and decaying plant matter undergoing microbiological deterioration. Ideal condtions for Aspergillus Fungi growth include high moisture (in excess of six percent) and high temperature.

Neither humans nor other animals are immune from the toxic effects of aflatoxin - though humans have an extraordinarily high tolerance to aflatoxin exposure.

High-level Aflatoxin exposure can produce, cirrhosis and carcinoma of the liver, acute liver damage, edema, and digestion problems including the inability of the body to properly absorb or metabolize nutrients.

Aflatoxin exposure was brought to the attention of canine owners in late 2005 when a number of canines became ill from eating contaminated dog food. Although, it is entirely possible that this mass episode of aflatoxin poisoning could have gone unnoticed, an alert veterinarian realized that several dogs in his care were exhibiting similar symptoms. Once brought to the attention of the public through media reports, the full extent of the problem was exposed. After investigation, it was determined that certain pet foods made by Diamond Brand Pet Foods at their Gaston, South Carolina plant, and distributed in 23 U.S. states, were contaminated with Aflatoxin. Contaminated pet food was distributed to stores in Alabama, Connecticut, Delaware, Florida, Georgia, Kentucky, Maine, Maryland, Massachusetts, Mississippi, Michigan, New Hampshire, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Rhode Island, South Carolina, Tennessee, West Virginia, Vermont, and Virginia, and in a number of countries, including several in the European Union, according to reports.

As pet owners began to stream into veterinary clinics with pets exhibiting signs of liver problems, the most discouraging aspect of aflatoxin poisioning became apparent. At Cornell, University Vet School in Ithaca New York, two thirds of the aflatoxin-exposed canines under their care, did not survive.

What should a pet owner do if aflatoxin exposure is suspected? First, be familiar with the symptoms of afaltoxin exposure which include lethargy, sluggishness, anorexia, vomiting, bloody diarrhea and yellowing of the eyes. If your pet exhibits any of these symptoms, seek veterinary care. Tests have been developed that can detect liver damage in dogs caused by aflatoxin exposure. If you believe that your dog may have eaten food contaminated by aflatoxin, ask your vet to order a lab test for confirmation. For more information on afllatoxin testing, go here [http://diaglab.vet.cornell.edu/news/aflatoxin.asp].

Undoubtedly, canine owners were alarmed when word of the Diamond Pet Foods dog-food recall hit the papers. However, as frightening as the incident was, it is important to remember that these kinds of episodes are few and far between. Dr. Karen Bischoff, a Veterinarian, Diagnostic Toxicologist, and Diplomate of the American Board of Veterinary Toxicology, observed that “[l]arge-scale contamination problems are a very rare event,” occurring only “a very few times in the past several decades.” Dr. Bischoff points out that many dog food manufacturers regularly test the ingredients that go into their pet foods and an increasing number are testing their foods post manufacture. Even so, she observes, “[n]o test method is fool proof and no food supply is 100% safe.” Since mold doesn't grow evenly in a batch of food (think of the way mold grows on cheese, or a bag of oranges, for example) it is possible to miss a "hot spot" of contamination. 

Of greater concern, is the possibility of contamination due to food spoilage. According to Dr. Bischoff, mold can grow and produce toxins on pet food just as it can on grain or anything else and that post-purchase handling of pet food by consumers is a more likely source of mycotoxin contamination than a manufacturing error. Even in the absence of mold growth, Bischoff adds, fats in the food can become rancid and vitamins can break down and these factors could cause animals to refuse to eat the food or, possibly, result in other health problems.

Since moisture, humidity, and warmth encourage mold growth and nutrient degradation, it is important to store pet food properly by keeping it in a cool and dry place. Food should never be allowed to become wet in the bag or in the container, Bischoff cautions. If you use containers to store your food, all the food in the container should be used and then the container should be cleaned, rinsed and dried prior to adding new food. Don’t just add new food on top of old food, Bischoff warns, otherwise you may just transfer any contamination present to the new food. Also, when purchasing dog food, do not stockpile it for longer than it takes your dog to consume in a month or so. Fresh food means that molds have less time to grow and produce toxins. Finally, it is also helpful, Bischoff suggests, for people who store food in containers to save the original bag or proof of purchase info, in the unlikely event that contamination occurs. This will help identify the manufacturer and lot number of food that you purchased.

Undoubtedly, Aflatoxin is a potentially serious threat to the health of our pets. However, it is a threat that is easily managed. Outbreaks caused by manufacturing are rare and contamination due to improper storage or sanitation is easily prevented. By keeping food cool, dry and stored properly, we can ensure that our pets remain healthy and happy.