Does Dry Dog Food Go Bad? Sooner Than You Think!

Just about every dog owner has been in that position where we buy dog food in bulk to save some money…but once you realize you still have a few unopened bags a year later, you’re probably starting to wonder if dry dog food can go bad.

Yes, dry dog food can go bad. The food in unopened bags can last anywhere between 12-18 months. However, food in opened bags should be consumed within two weeks. Once a bag is opened, it will be exposed to air and moisture, which will lead to harmful bacteria and mold.

Below we will go over a few ways to tell if the dog food has gone bad, but always remember…when in doubt, toss it out.

Signs Your Dry Dog Food Has Gone Bad

If you suspect the dog food might be bad, look for the following signs.

Check The Expiration Date (DUH)

The first thing you should do is check the expiration date on the bag. Most dry dog food brands will have an expiration date of 12-18 months from the time of purchase. However, this ONLY applies if the bag is unopened. If the bag has been opened, you should toss it out after two weeks.

Trust Your Dogs Nose (Not Yours)

We use our sense of smell to see if food has gone bad, but when it comes to dry dog food, you should trust your dog’s sense of smell over yours. If your dog normally eats their food but suddenly refuses, there’s a chance they could be smelling mold that’s not visible quite yet.

You can usually tell if that’s the case if your dog puts his nose close to the bowl to sniff it, then backs away. Again, this only works if it’s their usual food. If it’s a new brand, they might back away because they aren’t used to it.

The flaw with this method is that some dogs will eat just about anything regardless of how it smells. If you have a dog that devours everything in sight, this method won’t work.

Look For Visible Signs

When most of us pour food into the dog bowl, we rarely take a look at it. If you think the dry dog food might have gone bad, be sure to carefully inspect the food and check for mold or bugs. Also, look for different colors and a white powdery coating. All these are visible signs that the food has gone bad.

Related:  How to Store Dry Dog Food Long Term [Preservation Tips]

Watch Your Dog After They Eat

One of the most apparent signs that dog food has gone bad is when your dog gets sick or is in extreme discomfort after they eat. When dogs consume food that has expired, it will cause severe stomach irritation, which will lead to diarrhea, vomiting, and lethargy.

Of course, that doesn’t always mean it’s the dog food. Your dog could be sick with something else. But if that bag of dog food has been sitting around the house for a long time and your dog gets sick after consumption, there’s a good chance it’s time for a new bag.

Preventing Dry Dog Food From Going Bad

Now that you know the primary ways to tell if dry dog food has gone bad, let’s talk about a few things you can do to make the food last as long as possible.

Keep It In The Original Bag

One of the biggest mistakes people make when it comes to storing dog food is to store it in containers. Most dog owners don’t realize that dog food bags were actually designed to keep dog food as fresh as possible for as long as possible. They were made to keep critters out and let in as little oxygen as possible.

There are some dog food containers you can purchase that were designed to keep dog food as fresh as possible, but those can be a bit pricey. If you want to make the food last as long as possible, your best option is to keep the food in the original bag.

Don’t Mix New With Old

When you’re almost finished with a bag of dog food, you might be tempted to open up a new bag and pour the remainder of the old bag into the new one. If the old dog food had any bacteria or mold at all, it could transfer it to the new bag.

I understand the desire to save space, but the last thing you want to do is put your dog’s health at risk. Instead of mixing the old bag with the new bag, make sure you completely finish off the old bag, then open the new one.

Prevent Air From Getting In The Bag

When you’re done scooping out the dog food, make sure to completely seal the bag. The best way to do this is to tightly roll the top (this will release the oxygen) and then use a clip to seal it.

The reason it’s crucial to keep air out of the bag is that exposure to air will accelerate the growth of harmful bacteria. The longer the food is exposed to oxygen, the quicker it will go bad. Simply clip the top of the bag to make the food last longer.

Related:  How to Sterilize Deer Antlers For Dog Chews

Keep it Cool

As we all know, the cooler food is, the longer it will last. Dog food is the same. The general rule of thumb is heat makes food go bad, cold preserves food. You don’t need to keep the dog food in the fridge, but it is best if you can store it in a cool, dark place such as the pantry. During the cold winter months storing it in the garage is fine. But since garages can get warm during the summer months, it’s best to find another place to store the food during summer.

How Long Will Unopened Dry Dog Food Last?

Now that you know how to make dog food last as long as possible, you’re probably wondering how long it will last if you do everything right.

Let’s start with an unopened bag. As long as you keep the bag in a cold room, the food should last for well over a year. Check the expiration date on the bag. These expiration dates are for bags that remain unopened. Most bags will show an expiration date of about two years from the time of purchase.

How Long Will Opened Dry Dog Food Last?

To be on the safe side, you’ll want to finish the bag within 14 days of opening. I know that doesn’t seem like a lot of time, but you need to remember that when it comes to food spoiling, the enemy is oxygen.

Right when the bag is opened, the food is exposed to oxygen, and there will be a chemical reaction that begins the process of spoiling. That’s why it’s best to purchase smaller bags. I know you save a bit of money when purchasing big bags, but unless you think you’ll finish it off within two weeks, it’s best to buy multiple smaller bags.

Health Risks of Eating Food Past “Best By” Date

One of the main questions we get asked when it comes to dog food is whether or not it’s ok for a dog to consume food past the “best by” date.

Technically you could probably get away with it. As long as it’s not too far past the “best by” date, it should be fine. However, we always prefer to play it safe when it comes to the health of our dogs. Because of this, once that date has passed, we toss the food.

Be aware of the following health risks before giving your dog food that is past the “best by” or “expiration” date.

Health Risks of Non-Contaminated Food (No Bacteria, Mold, or Bugs)

Digestion Issues

Just because there are no visible signs of bacteria or mold doesn’t mean the food hasn’t already started to spoil. If your dog eats spoiled food, it can lead to digestion issues such as diarrhea and vomiting.


Malnutrition is a risk for two reasons. First, if your dog does get diarrhea or vomiting from the spoiled food, they won’t be getting all the essential vitamins and minerals required to keep them healthy. The second reason malnutrition is a risk is that when the food begins to spoil, the quality of the nutrients goes down. If this happens, you may notice your dog becoming more sluggish and lazy.

Related:  How to Sterilize Deer Antlers For Dog Chews

If The Food Has Been Contaminated

Once the food has been contaminated, the severity of the health risks increase. If you’re going to feed your dog food that is past the expiration or “best by” date, make sure you check for mold before your dog consumes it.

The health risks include the following:


This is a rare disease that can affect dogs who eat spoiled dog food that contains meat. Symptoms usually begin within six hours and eventually lead to paralysis of all four legs.

E. Coli

Although E. Coli is more common in newborn puppies, adult dogs can suffer from this disease if they eat contaminated/spoiled food. E. Coli causes a high presence of bacteria in the blood (AKA blood poisoning).


A mild case of salmonella isn’t considered dangerous. Your dog might feel a bit under the weather and lethargic but will return to his usual self within a few days. However, a severe case of salmonella will include a high fever and loss of blood in the stool.

Although the above three health risks are rare, it doesn’t change the fact that they’re still a risk. That’s why we recommend playing it safe and buying a new bag of food instead of feeding your dog food that is past the expiration date.

I know it’s tempting to buy big bags of dry dog food to save money, but remember it’s best to finish the bag within 2 weeks of opening.

Recommended For You