TL;DR: Use an opened bag of dry dog food within about 2 to 3 months, and never past its "best by" date. Keep the kibble in its original bag, set the whole bag inside an airtight container, and store it somewhere cool and dry, below 80°F. Opened canned food keeps for up to 72 hours in the fridge.
How long does dry dog food last after opening?
Unopened, dry dog food is good until the "best by" date printed on the bag, often a year or more from manufacture. Once opened, the clock speeds up. Veterinary nutritionists at Tufts University's Cummings School recommend using an opened bag within 2 to 3 months.
The reason is fat. Kibble is sprayed with fats and oils for flavor and calories, and once the bag is open, oxygen, heat and humidity start oxidizing those fats. Rancid fat makes food less appealing, degrades vitamins, and can upset some dogs' stomachs. The preservatives in the food slow this down, but they can't stop it indefinitely.
A practical rule: buy a bag size your dog will finish in about 6 to 8 weeks. The bigger bag is cheaper per pound, but only if you use it before it goes stale.
Keep it in the original bag, even inside a container
This is the most common storage mistake. Pouring kibble straight into a bin and throwing the bag away seems tidier, but the FDA and veterinary nutritionists both recommend keeping food in its original bag and putting the whole bag inside a clean container with a lid. There are two reasons:
- The bag is designed as a barrier. Pet food bags are engineered to keep out oxygen and moisture and to hold in fat. A plain bin doesn't do that job as well.
- The bag has the information you need in a recall. The lot number, UPC and best-by date identify exactly which batch you have. Without them, you can't tell whether a recall applies to your food. See why this matters in why a brand's recall history matters.
If you do pour food directly into a container, cut out the part of the bag with the lot number and best-by date and tape it to the lid, and wash and fully dry the container between bags. Don't top up old kibble with new: the fat residue left on the container's walls goes rancid and contaminates each fresh batch.
Where to store it
- Below 80°F. Heat speeds up fat oxidation and nutrient loss. A pantry or closet is better than a garage, which can get far hotter in summer.
- Dry. Humidity invites mold. Keep bags off damp basement floors and away from the dishwasher and laundry.
- Sealed. Roll the top of the bag down tightly or use a clip, then close the container lid. This keeps out pantry pests and stops a determined dog from helping itself.
For container options that avoid plastic, including stainless steel and glass bins sized for full bags, see our guide to plastic-free pet food storage.
How long does wet dog food last once opened?
Much less time. Cover an opened can, refrigerate it promptly, and use it within 72 hours (Tufts' recommendation). Don't leave wet food sitting in your dog's bowl at room temperature for hours: bacteria multiply quickly in moist food. Canned food shouldn't be frozen in the can; freezing can change its texture and taste.
Signs dry dog food has gone bad
- A sour, paint-like or "off" smell instead of the usual savory one, a sign of rancid fat
- Visible mold, clumping, or a damp feel
- Insects, webbing or larvae in the bag
- Your dog suddenly refusing food it normally eats, or vomiting or diarrhea after meals
If you see any of these, throw the food out in a sealed bag. If your dog gets sick, keep the bag or at least its lot number, since you may need it to report a problem to the manufacturer or the FDA.
Quick reference
| Food | How long it lasts | Store it |
|---|---|---|
| Dry kibble, unopened | Until the best-by date | Cool, dry place below 80°F |
| Dry kibble, opened | About 2 to 3 months, and not past best-by | Original bag, inside an airtight container |
| Canned food, opened | Up to 72 hours | Covered, in the fridge |
Reviews & Comments
Loading...