Can Dry Dog Food Go Bad? How To Know If It’s Spoiled
Can Dry Dog Food Go Bad? How To Know If It’s Spoiled


Dry dog food can go bad, but not as quickly as wet pet food. However, dry kibbles will start to lose their nutritional value and become stale.
Dry dog food is a convenient way to feed your pet. You don’t need to worry about adding water or managing how much food to buy as much, and it’s easy for them to eat.
And its common knowledge that most wet dog foods will expire much quicker than dry kibble. Dry dog food will eventually become spoilt over time.
But when does dry dog food go bad? How can you tell if it’s spoiled? Read on to find out more!
What Causes Dry Food To Become Spoiled?
Dry dog food is manufactured in a specific way that kills off harmful bacteria and fungi. So why does it expire?
Once it’s opened, nothing is preventing these bacteria from forming. Holes in a dog food bag are often the main route bacteria and fungi use to fight back because of the air and moisture getting in.
Exposure to air allows airborne bacteria to grow, speed up fat oxidation, and create toxic byproducts.
Fungi also thrive in a moist environment (as well as bacteria). In fact, despite the fact your dog’s food is “dry” it still contains approximately 14% moisture.
Below are some examples of dry dog foods and their moisture content:
Product | Moisture (Guaranteed Analysis) |
Blue Buffalo Life Protection Chicken Dry Dog Food | 10.0% max |
Purina Pro Plan Sensitive Skin & Stomach Salmon Dry Dog Food | 12.0% max |
Hill’s Science Diet Adult Large Breed Chicken Dry Dog Food | 10.0% max |
ORIJEN Regional Red Grain-Free Dry Dog Food | 12.0% max |
Purina ONE SmartBlend Lamb Formula Dry Dog Food | 12.0% max |
Rachael Ray Nutrish Real Chicken Recipe Dry Dog Food | 10.0% max |
*Information accurate as of 10/5/2021 according to chewy.com
Because of the moderate amounts of moisture, an accumulation of added moisture will allow bacterial and fungal formulations to happen.
Finally, storing these types of dog foods in excessive temperatures will accelerate the growth of organisms and the rancidity of fat. [1,2,3,4,5]
Generally, the inclusion of preservatives prolongs the “shelf-life” of dry dog food formulas and prevents bacteria and fungi from growing. However, it does not stop it completely. After a certain amount of time, dry dog food will start deteriorating.
After the dog food’s expiry date has gone, the nutritional content of the formula is highly toxic and might contain highly hazardous bacteria and substances.
Some scientific studies have shown that fat degradation is the main source of spoilage for pet food. So many low-fat diets will generally have a longer best-by-date.
If you’re looking for a diet that lasts longer, consider trying a low-fat diet for your pup. Always be sure that the formula you’re feeding them meets their minimum fat requirements. [6]
How long can dry kibble last?
Dry dog food is a convenient way for dog parents to feed their furry friends. Not only this, but the food’s prolonged shelf life makes it a cost-effective solution too.
As previously mentioned, dry dog food can extend its shelf-life by removing moisture. But, added preservatives play a role in this too. [1]
There are two types of preservatives that you may encounter; natural and artificial preservatives.
Added antioxidants like specific minerals and vitamins can also play a role in extending shelf life. These compounds are also nutritionally beneficial for your pup, help prevent free-radical damage, and prevent rancidity of fat. [7,8,9]
There are distinct differences between “best before/ by” and “expiration date” that you need to be aware of when purchasing dog food.
If your dog consumes food that is past its best-by-date, it can still be safe for them to eat, but it is still not recommended. Generally, a best-by date is an indication of when the flavor, nutritional value, color, or smell can no longer change.
Whereas, an expiration date is an indication that the food is no longer safe for your pup to eat. This is primarily due to the preservatives no longer preventing the degradation of the food.
We advise you not to feed your dog such food if this is the case.
It is also worth noting that any best before/ by or expiration dates only apply to unopened bags. Once these are opened, then most dry kibbles will last for a few weeks.
However, if left unopened, and well-sealed, some dry dog foods can last up to 12 months. This largely depends on the ingredients and content of the recipe. [10]
How can I tell if my dog’s dry food is spoiled?
- Take a look at the dog food bag. Does it have any noticeable mold on it or bugs? Can see any moisture inside the bag?
- Smell the dog food. Does it smell acidic or “off”? If you think it does, then it’s likely it is.
- Has your dog recently been “picky” with the food? Your dog’s nose is powerful! If they are, closely inspect the food to see if it’s spoiled.
- Is the food greasy to touch? Can you feel excessive moisture?
- Re-check the expiration date on the packaging again.
In the future, try writing on the bag when you open it. This will give you a rough guide of how long the food has been opened for, and prevent feeding your pup anything potentially hazardous.
If anything is noticeably wrong with the food, take it back to the original place of purchase immediately.
Some things to look out for when buying dry dog food
Whenever you are purchasing dry kibble formulas, always check the best-by or expiration dates. Obviously, you want to be purchasing something with the longest possible period before spoilage occurs.
Also, take a look at the food label and see if it contains any preservatives. If you strongly believe your dog will eat the diet before 3 weeks, I would recommend looking for a formula that contains non-synthetic preservatives.
Synthetic preservatives will generally prolong the shelf life of a formula. As a dog owner, you may be questioning this. However, these types of preservatives are less likely to harm your pup compared to rancid food.
Finding the best dog food for your furry friend can be difficult. However, always consider the ingredients in the diet too. There should always be an animal, meat-based protein source with high-quality, whole ingredients in it.
Finally, always be sure to follow the storage instructions recommended by the pet food manufacturer. Try not to bulk buy your dog’s food either, unless you can freeze it for a long time.
Final Thoughts
We all value our lovable furry friends and think of them as part of our family. And just like you, you wouldn’t eat anything that could be potentially harmful.
Let’s be honest, we all know how much dogs love food!
Most dry dog foods are a convenient, cost-effective solution for many pet parents. But they can, and do, go “off” after a while. Food is an essential part of a dog’s everyday life and activities.
While feeding your dog rancid food won’t have an immediate effect on them, it will over time and can cause serious, life-threatening conditions.
Consult your veterinarian if you have any immediate concerns over your dog’s diet.