Keeping an open bag of dry dog food for weeks in your kitchen or garage will cause changes in the food that may lead to serious health problems. Learn how to properly store dry dog foods to help your dogs and cats live longer.
Would you keep a loaf of bread in your kitchen for 39 days?
We hope not. That’s how long the typical opened bag of dog food lasts. This lengthy storage time and often poor storage conditions lead to nutrient degradation, oxidation of fats, and infestation by molds, mites and other food spoilers. One in three dogs dies of cancer, and we think improper storage at home is a major contributing factor.
Dry dog foods usually have a one-year “shelf life.” That means the food is “good” for up to one year after the manufacturing date. Many dry foods stamp a “best if used by” date on the package. This applies only to unopened bags.
High-quality dog food companies use bags that provide protection from oxygen and moisture. If the bag is intact, not enough oxygen and moisture can migrate into the food in one year to cause significant oxidation or microbial growth problems. Though there are problems which can occur between the manufacture of food and the customer opening the bag, it’s what happens after the bag is opened that we are most concerned with in this article.
What happens after you open the bag of dog food
As soon as you open a bag of food, oxygen, moisture, light, mold spores, storage mites, and other potential spoilers enter the bag.
Oxidation of fats
Oxydized fats may cause cancer and contribute to many chronic health problems in humans. The same is true for dogs.
Dog food companies use antioxidants (sometimes vitamin E and other natural sources) to forestall oxidation. Every time the bag is opened, oxygen enters. Eventually the antioxidants are all oxidized (used up) and some of the fats are damaged, starting with the more fragile omega –3 fatty acids, which the better pet food companies now add to their foods.
Degradation of all micronutrients
Vitamins particularly susceptible to oxidation and damage due to long term room temperature storage include vitamin A, thiamin, most forms of folate, some forms of vitamin B6 (pyridoxal),vitamin C, and pantothenic acid. The nutrition in the food at the bottom of a bag left open 39 days will be considerably less than the nutrition in the top of the bag. The fresher the better.
Molds and mycotoxins
Storing open bags of dry dog food for 39 days in warm, humid areas (most kitchens) promotes the growth of molds. Some of the waste products of these molds (mycotoxins) are increasingly being implicated as long-term causes of cancer and other health problems in humans, poultry, pigs and other animals. Dogs are particularly susceptible to these toxins (1).
When dry dog foods absorb moisture from the surrounding air, the antimicrobials used by most manufacturers to delay mold growth can be overwhelmed(2), and mold can grow. The molds that consume dry pet foods include the aspergillus flavus mold, which produces aflatoxin B 1, the most potent naturally occurring carcinogenic substance known (3).
You can’t see low levels of mold, and most dogs can’t taste it.(4) While many dogs have died shortly after eating mycotoxin-contaminated foods (5), mycotoxins kill most dogs slowly by suppressing the immune system and creating long-term health problems in all organs of the body(6) .
Bugs, storage mites, mice, and other unpleasant invaders thrive on dry dog food. Recent research has shown that allergic dogs are frequently allergic to the carcasses of storage mites, which may infest grains, especially those grains used in low cost dry dog foods.
Here are our recommendations:
Keep food in its original bag, even if you use a container. Plastics can leach vitamin C out of the food. The components of the plastics themselves may leach into the food. Rancid fat which lodges in the pores of plastics that are not food-grade will contaminate new batches of food.
Buy small, fresh bags of food; only enough to last 7 days. Look for manufacturing or “best if used by” dates on the bag. If you don’t see one, or can’t understand the code, write the manufacturer and ask where it is or how to interpret their codes.
Keep food dry . If the food looks moist, throw it away.
Keep larger bags in the freezer. This is the only way we think large quantities of food may be kept safely.
If the food has off color, throw it away.
If the food smells rancid or like paint, throw the food away.
If your dog says no, do not force her to eat.
Don’t buy bags that are torn.
Follow these simple recommendations and you will radically reduce the deadly toxins your dog or cat encounters. May your Spot live a long, healthy life.
1. Bingham, Phillips, and Bauer. “Potential for dietary protection against the effects of aflatoxins in animals” Journal of the American Veterinary Medical Association, Vol. 222, No. 5. March 1, 2003. 593.
2. The data we’ve seen from manufacturers of antimicrobials shows that after four days at above 12% moisture mold growth starts.
3. From Science News, Vol 155, No 4, January 23, 1999 p 63.
4. Hughes, Graham & Grieb “Overt Signs of Toxicity to Dogs and Cats of Dietary Deoxynivalenol”, Journal of Animal Sciences, 1999. 77: 699-700.
5. Chafee and Himes, “Aflatoxicosis in Dogs,” American Journal of Veterinary Research, Vol 30, No 10, October 1969, p 1748.
6. Council for Agricultural Science and Technology, Ames, Iowa, USA Mycotoxins: Risks in Plant, Animal, and Human Systems January 2003 32.
Contributed and © Steve Brown and Beth Taylor Authors of See Spot Live Longer