Worryingly, a number of animal studies have indicated that vitamins in food are destroyed when oils and fats go rancid (Source: Pavcek PL, Shull GM. J Biol Chem 146(2):351-5, 1942). This means that when your dog consumes old kibble, they may not be absorbing all of the nutrients, vitamins and fats they need for a healthy, well-balanced diet.
Pet food bags are designed to keep kibble stable and safe for your pet to eat. But, when a bag is opened, and the kibble is exposed to air, the oils and fats in the food start to react with oxygen, gradually causing them to break down and eventually turn rancid (a term used to refer to spoiled food, which in the case of kibble can be detected by a plastic, chemical-like smell). Sounds yucky, doesnt it?
So how long does a bag of dry pet food really last after its been opened?
Why does a bag of kibble only last for 2 weeks once opened? Its all down to a sneaky process called oxidation.
What about the expiration date on the bag, you ask? While it is true that the shelf-life of an unopened dry dog food product can be up to a year, once a bag of kibble is opened, the two-week count-down begins, making the expiration date on the bag somewhat misleading.
Whether you choose dry dog food, wet food, or a combination of both, it is important to know just how fresh the food is that you are feeding your pet. And while we sometimes forget that even dog food can have a best by date, it can be important for the health of our dogs.
When we unseal the dog food for the first time, we are exposing it to the elements, from moisture in the air to heat or cold, and that can degrade the integrity of the food. This means that in the case of dry food, you will want to use the opened bag within a few weeks. And although using a plastic storage container can help with shelf life, it is not going to give you back all the time you had before you opened the bag, because the food has already been exposed to the air and moisture.
Although both wet and dry foods are made to last for a while, that does not mean it will stay fresh forever. And that is important for us to remember, because it certainly isn’t fair to our pups to feed them stale food, just like we don’t want to feed them bad food.
Another tip for using plastic storage containers in order to keep food fresher for longer, is the recommendation that you not pour the food directly into the container. Instead, leave it in the bag it came in, because otherwise the oils from the food can seep into the plastic, and leaving behind a residue that can ruin future food that is stored in the container. (We all have that one piece of plastic Tupperware that is stained from tomato sauce or something oily that we stored in it, and the same thing happens with dog food, especially if you are just pouring dry food on top of dry food.)
As the Dog People by Rover explained, it is possible for dog food to go rancid or spoil, even if there are some things we can do to keep our pet’s food fresher for longer. Depending on the type of food you feed your dog, you may have a longer shelf life on a product than you thought. It is all about paying attention to everything from the expiration dates to the proper storage techniques.
Bottom Line: How Long Does Dog Food Last?
Different types of food stay fresh and tasty for various amounts of time based on how they’re prepared and preserved. Here are some basic guidelines on how long you can expect each Fido food type to keep.
While it can be tempting to buy food in bulk for the price cuts, it may make sense to buy smaller quantities instead and enroll in an “autoship and save” program. This will not only eliminate the need to order your dog’s food each month, but by buying smaller quantities, it’ll help keep your dog’s food as fresh as possible.
For example, if you have a smaller furry friend, you probably don’t want the largest bag of kibble you can find since it will take a while for your dog to make his way through the bag. This can lead to the food becoming unsavory or unsafe over time, so make sure you’re purchasing food that’s proportionate to your pooch’s eating habits.