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How long does dog Kibble last, & what's the best way to safely store it?

Here's an interesting question... What’s more expensive … your dog’s kibble or the bag it comes in? Pet food companies invest heavily in packaging. Packaging with compelling pictures & graphics helps make sales, & it's also critical to the safety of the dry products inside. It's been developed & tested so it can sit on the shelf for months or years & so the food will still hold much of its nutrition. The packaging's job ends when you open up that bag of dry bikkies. As soon as you open it, the food changes quickly, & those changes can be toxic to your dog. So how long does that bag of kibble really last?

How long does a bag of Kibble stay fresh?

How Long Does Kibble Last?

You may be surprised to learn that Kibble lasts only 2-3 weeks once the bag is opened. That’s far shorter than the “Best Before” date on the bag … which is usually at least a year. But this date applies to unopened bags of food. Once opened, food loses its nutritional value and the fats begin to oxidise and go rancid. And every time the bag is opened, air gets in and the problem gets worse. Here’s why …

How do they make Dog Food last for years?

The main reason kibble is heated and dried is to remove the moisture from the food. Moisture is the enemy of any food that needs to sit on a shelf for months or years … because moisture breeds bacteria. Most dry dog food kibble contains only about 10% moisture for this reason.

Once the kibble is dried, the packaging is critical to the stability of the food. If air got into the food on the shelf, it would become oxidised. Oxidation happens when the chemicals in the food come into direct contact with oxygen. Oxidation lowers the nutritional value of the food … and can also cause toxic mould and bacteria to grow.

The most dangerous result of oxidation is how it damages the fats in the food & this is why most packaging has a grease barrier. The barrier usually contains a synthetic antioxidant to prevent the fats from oxidising & becoming rancid. So with the proper packaging in place, the pet food manufacturer can send that food out on pallets … and it can sit on the shelf with a “Best Before” date so you feel safe knowing the food you buy your dog isn’t spoiled.

While AAFCO requires pet food companies to put a “Best Before” date on your food, they don’t have to say when the food was manufactured. So you don’t know how long the food has been sitting on the shelf before you buy it.

What happens when you open the bag? Why Fats In Kibble go Rancid fast

The minute you open your dog’s bag of kibble, air gets in and the oxidation process begins. And every time you open the bag, the amount of oxidation increases, along with the health risks.

The fats and oils in the food are very susceptible to oxidation … so every time you open the bag, the fat particles break down into smaller compounds (these are dangerous chemical compounds), and the fat becomes rancid.

The Problem With Rancid Fats

Here’s why you don’t want your dog to eat rancid fats.

  1. Rancid fats can destroy vitamins, which can lead to vitamin deficiency. Most dogs today are vitamin D deficient which is why a lot of companies include Synthetic Vitamin D.

  2. Rancid fats have been linked to many other health issues … including malnutrition, hair loss, diarrhoea, liver and kidney disease, reproductive problems and even cancer and death.

What types of fats are in Kibble?

There are many types of fats and they’re divided into the number of carbon bonds they contain. And the more carbon bonds the fat contains, the more quickly it will oxidize.

  • Saturated Fats, like those found in beef, contain no carbon bond so they’re not as unstable as other fats.

  • Monounsaturated Fats contain one double bond, meaning they oxidise more easily. Olive oil is an example of a monounsaturated fat. But the amount of oxidation isn’t nearly as much as it is in polyunsaturated fats.

  • Polyunsaturated Fats contain several carbon bonds. Chicken fat contains polyunsaturated fats, so foods with chicken or poultry fat are much more likely to oxidise than those made with Beef fats.

The fats with the most bonds are DHA and EPA … the fats found in fish oils.

Try to avoid Kibble containing Fish Oil

It may seem like a great healthy oil for your dog, 9& it is!) BUT fish oil is extremely unstable. So even if it’s not oxidised & rancid right after the kibble is made … it will become rancid extremely quickly once the bag is opened putting your dog’s health at risk.

Never buy kibble with fish oil added. If you want to give your dog fish oil, buy it separately & add it to his diet. But never feed him kibble with fish oil already in it, it’s highly likely to be rancid.

Antioxidants In Kibble

Pet food manufacturers know about the problems with oxidation. So they use antioxidants to slow down the rate of oxidation, & add antioxidants to your dog’s kibble in two forms:

  1. Antioxidants that your dog’s cells can use to protect against the free radical damage from rancid fat.

  2. Antioxidants your dog can’t use … but that help preserve the food. If an antioxidant is used, AAFCO requires the pet food company to use the common name of the antioxidant, along with the fact that it’s used as a preservative. This will show up on the ingredient list next to the preservative name … for example “Sorbic Acid (used as a preservative).”

Synthetic Preservatives In Kibble

Synthetic antioxidants are a controversial addition to pet foods. Some better brands have stopped using them because of their impact on health. There are four common synthetic antioxidants used in the manufacture of kibble.


Ethoxyquin keeps pet food fresh … but it’s also a pesticide! It’s not approved as a direct food additive in foods made for human consumption …. but it’s still in pet foods. The FDA allowable amount in human foods is .5 to 5 ppm but in pet foods it’s 150 ppm.

If your dog’s food contains fish meal, it contains ethoxyquin, as it is required by law when transporting fish meals. But because the ethoxyquin isn’t added directly to the pet food, AAFCO doesn’t require the manufacturer to put it on the ingredient list.


Both BHA & BHT are artificial preservatives that have been linked to cancer in lab animals. BHT is also suspected to cause developmental defects & thyroid changes.


TBHQ, or tertiary butylhydrquinone, is an antioxidant derived from butane. It’s also used to make varnishes and paints. TBHQ has been found to cause stomach tumors and it’s also been linked to many other forms of cancer.

Always look for Natural Preservatives In Kibble

Natural preservatives, such as vitamin E (which is usually called mixed tocopherols) and vitamin C (normally called ascorbic acid) are used in better-quality foods. But while natural preservatives are less toxic than their synthetic counterparts, they don’t offer the same shelf life. And while they’re less toxic, not all “natural” preservatives are, well, natural!

Some of the more common natural antioxidants include:

Mixed Tocopherols

These are technically synthetic as they’re isomers of vitamin E extracted from vegetable oils and restaurant grease. The most effective tocopherol is gamma-tocopherol, which is derived from cereal grains

Rosemary Extract

Rosemary extract is an oily residue derived from the leaves of the rosemary plant. It prevents the oxidation of fats and protects flavours. Most industrial plants use solvents such as acetone, hexane or methanol to extract the oil. Rosemary extract is added to fat as a blend or premix, which can also contain mixed tocopherols, citric acid, emulsifiers and a vegetable oil carrier.

Citric Acid

This is produced by the fermentation of crude sugars. Citric acid is generally recognised as safe (GRAS) and is used In both the human and pet food industries. Instead of using synthetic vitamins E & C or rosemary extract, some pet foods will choose to use fruits containing citric acid, such as cranberries, blueberries or apples to defend against oxidation.

5 Tips To Keep Kibble As Safe As Possible 

Use these 5 tips to make sure your dog is getting the best nutrition possible from his kibble.

Know How Your Dog’s Kibble Is Preserved

If you’re looking for food-based preservatives instead of synthetic chemicals and vitamins … good for you! But be aware that your food won’t last as long.

Know What Fat’s In The Kibble

How long your pet food lasts once it’s opened depends on what fats are in the food. If your dog’s kibble is beef, then you need to use the bag up within 3 or 4 weeks. But if it’s chicken or other poultry, the PUFAs will degrade faster & you should use the food within 2 weeks of opening. If there's added Fish Oil, horrifyingly it's only going to last 1 week after opening!

Don’t Buy Big Bags Of Food

Larger bags of food will indeed cost you less, but your dog needs to get through that bag in 2 to 3 weeks before it goes rancid.

Don’t Buy Kibble With Fish Oil Or Omega-3 Fats Added

Fats from fish and fish oil oxidize very quickly. If you must feed a food with fish, use it up within a week for best results. 

Never Take Your Kibble Out Of The Package

To answer the question - surprisingly most pet food makers spend more on the package than the contents, & that bag is designed to keep oxygen out. Invest in an air-tight plastic container. Put the whole bag in the tub … then squeeze as much air out of it as you can and seal it with a clip.

So, in summary Kibble containing Beef Fat will last 3 or 4 weeks. Kibble containing Chicken Fat you will need to use it up within 2 to 3 weeks. If the Kibble has added Fish Oils you will need to use it up within 1 week.

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