
Has your cat recently eaten food that is spoiled or has gone bad? I know how worrying that can be for you as a cat owner.
You may wonder if your furry friend will be okay or if you need to rush them to the vet.
Cat has a robust enough digestive system to handle food that has gone bad. But there is always a risk of contamination. Food poisoning can cause side effects like vomiting, diarrhea, dehydration, fever and even tremors. It is best to be aware of the freshness of your cat’s food.
In this article, the importance of understanding the risks associated with your cat eating spoiled food and the steps you can take to ensure its safety.
When Is Food Considered Spoiled?

It is important for you to know the signs of food that have gone bad to protect your cat.
It Smells Gross
The first thing you’ll notice when pet food has gone bad is the smell. On the surface, it might look fine but the rancid smell can make your eyes water.
The odor can come from the food that is decomposed by the bacteria. Or it could be stinky chemicals that are released by the bacteria themselves.
If your cat’s food smells ‘off’, it’s best to throw it away.
It Looks Weird
If you see any weird colors like black, blue, green or yellow on the food that isn’t supposed to be there, it has probably gone bad.
The discoloration is caused by the microbes that have taken up residence in the cat’s food usually in the form of fungi or spores.
It Feels Slimy
If you are feeding your cat raw meat or canned cat food, another way to know when it has gone bad is by touch.
Food that feels, sticky, slimy, slippery or tacky is a good enough sign that it has gone bad and should be thrown away.
Can Cats Get Sick From Eating Rotten Food?
There might be times when your cat has consumed cat food that has gone bad or decided to empty your garbage bin of thrown leftovers.
Most cats are able to get away with it but eating food that has been contaminated can cause problems for some kitties.
Salmonella
Salmonella poisoning is very much a big concern when it comes to feeding cats a raw meat diet. Salmonella is usually transmitted when your cat eats raw meat that has been contaminated by animal feces.
It can also be transmitted on raw meat during the packing process when hygiene standards aren’t great.
Symptoms of salmonellosis in cats include:
- Vomiting
- Diarrhea
- Mucus in the stool
- Lethargy
- Unexplained weight loss
I understand that many cat owners are hesitant about transitioning their cats to a raw diet due to the risk of salmonellosis.
I have been feeding my cat raw food for more than a decade and he never had any problems. The same goes for numerous pet owners that have made the switch too.
Buy your meats from a reputable source and prepare the meat in a clean environment.
Botulism
Botulism is a form of food poisoning that is caused by the bacteria called Clostridium botulinum. This bacteria can be found in decaying meat and vegetable matter.
This bacteria releases a toxin that can cause paralysis of some of your cat’s body system like its muscles or even cardiac paralysis.
It can also cause the common side effects of cat food poisoning like diarrhea, vomiting and lethargy.
Listeriosis
Listeriosis is a bacterial infection that is caused by the pathogen Listeria monocytogenes. This bacteria can be found in canned cat food, raw food and dairy products.
The scary part about listeriosis is that not only can it be transmitted to your cat from ingesting spoiled food but also from inhaling it.
Listeriosis causes similar symptoms as botulism with paralysis one of the more severe side effects.
How Long Does It Take My Cat To Get Sick After Eating Something Bad?
The time for a cat to get sick after eating spoiled food depends on the specific food item and your cat’s immune system.
It can show start to show signs of food poisoning as quickly as a few hours. But for most cats, it can take anywhere between 24-72 hours to show any signs of an adverse reaction.
What Should I Do If My Cat Ate Spoiled Food?
“Observe your cat for a day to see if there are any symptoms.”
The first thing that you should do is take note of how spoiled or bad the food has degraded.
If your cat has eaten raw meat or wet food that has been left out for a few hours, that should still be ok for your cat.
Observe your cat for a day to see if there are any symptoms.
The first signs that your cat has eaten something wrong are usually diarrhea, vomiting or regurgitation.
My cat has diarrhea from time to time but it usually stops within a few hours. But if these symptoms carry on for longer than that, you need to take your cat to the vet immediately.
Your cat might require medical treatment like an IV drip or an antitoxin injection to get rid of any infection in its body.
If you have a kitten, senior cat or a cat with a compromised immune system, it might be better to give the vet a call to see if there’s a need to bring it in.
These cats can fall sick more easily due to their weaker immune systems.
Why Cats Are Able To Eat Spoiled Food?
Although eating infected food or food that has gone bad isn’t ideal for our cats, it might be of some comfort for you to know that cats have a much stronger digestive system than us.
Your cat might not have the digestive prowess of a hyena or a vulture that can eat the carcass of a dead animal but it can hold its own against food that isn’t too fresh.
There are several stages of defense that your cat has to prevent itself from getting food poisoning caused by contaminated food.
Firstly, cat saliva contains proteins and enzymes that are able to neutralize most bacteria found in the food they eat.
These natural antibacterial agents help prevent too many dangerous microbes from entering your cat’s body.
Secondly, cats have a very acidic stomach which allows them to safely eat spoiled meat or rotten food safely.
They also produce 10 times more stomach acid and a tremendous amount of bile as compared to humans.
Thirdly, cats digest their food very quickly taking between 10-24 hours to completely digest and absorb their meals.
This doesn’t give a lot of time for harmful bacteria to stay long in their intestinal tract and make the cat sick.
Can Cats Recover From Food Poisoning?
How quickly your cat can recover from food poisoning depends on how bad the symptoms were. For minor cases, it can just a few days for your cat’s digestive system to normalize itself.
More severe cases might require your cat to be hospitalized and put under observation.
If your cat has just recovered from food poisoning, do not start feeding your cat anything that can upset its digestive system for now.
That means noting dairy in nature or unhealthy human food as snacks.
If your cat is on a raw food diet, you can try giving your cat wet cat food or cooked meat for a couple of days first until it is fully recovered.
How Long Can You Leave Cat Food Out For?
This section is very important for all pet owners as it gives you a good gauge of determining the freshness of your cat’s or dog’s food.
Not all types of cat food degrade at the same rate so we will go through the different food types to give you a better idea.
Dry Cat Food
“This lack of moisture is a double-edged sword for your cat.”
Dry cat food is a very common diet for many domesticated cats. It is convenient and affordable for pet owners to feed their cats with kibbles or dry food.
Dry food can last the longest out in the open as compared to the other food types due to the lack of moisture in the dry food.
This lack of moisture is a double-edged sword for your cat.
It allows for dry food to be left out in the open for 4-5 hours before it starts to get stale. Moisture is a great catalyst for food contamination which dry food doesn’t have.
As resilient as dry food or kibbles can be, dry food can still go bad if left out long enough.
There are some cat owners that free-feed their cats with a bowl of kibbles that is left out for days.
Please do not do that as even though it might seem ‘fresh’, the onset of contamination has already begun.
The lack of moisture in dry food is bad for your cat. Cats normally hydrate themselves from the food that they eat. The lack of moisture can lead to kidney problems in the long run.
Wet Food
Wet food or canned food is the next most popular type of diet for cats. Many cat owners do feed a combination of both dry and wet food to their cats.
Wet food is a lot healthier for cats but the moisture in wet cat food makes it more prone to contamination within a shorter time frame than dry food.
When I was feeding my cat wet food, I only leave it out for a maximum of 2-3 hours.
Anything left over after that is thrown away to prevent my cat from eating spoiled food.
If you need to leave wet food for your cat before your leave the house, you can place your cat’s food bowl in a plate of ice cubes to keep it fresher for a longer time.
I wouldn’t suggest that you heat up old wet food just to ‘freshen’ it up.
Although many cats like warm wet cat food, heating up wet food that has gone bad will not get rid of the pathogens and toxins on it.
Be aware of the expiration date of the canned food that you buy.
Raw Food

Raw food is easily the most sensitive of the three types of diet for your cat. It has a lot of moisture which is conducive to bacterial growth and it is raw.
This means that the food didn’t go through a heating process to eliminate whatever nasty pathogens that are residing in the meat before feeding the cat.
But do not let this deter scare you as the raw meat diet is the best diet that you can give your cat.
I do not leave out raw food for longer than an hour for my cat or dog. 1.5 hours is the longest I will go.
I use ice packs to keep the raw food fresh for as long as possible if I need to feed and leave home for a few hours.
Pets are smart and intuitive to know when the food has gone really bad and not touch it until I get back and feed them a fresh batch.
To minimize food contamination in raw meats, get your meats and organ meats from a reputable source and wash your hands before handling the food.