Can cats eat wet food that’s been left out?

Cats are notorious for being finicky eaters. Many cat owners have experienced the frustration of carefully preparing or serving wet cat food, only to have kitty turn up her nose. This often leads to wet food sitting out for a period of time before Fluffy decides she’s ready for a nibble.

Quick Answer

The quick answer is no – cats should not eat wet food that has been left out or neglected for an extended period of time. Wet or canned cat food should be consumed within 30 minutes to 1 hour of being served. Leaving wet food out can allow bacteria to grow to unsafe levels.

How Long Can Wet Cat Food Sit Out?

Fresh, just-opened canned cat food can safely sit at room temperature for up to 1 hour. Pouches or tubs of fresh wet food, once opened, can safely sit out for 30 minutes. Any wet cat food that has been left out for longer than these time frames should be thrown away.

1 Hour for Canned Food

Once opened and poured into a bowl, canned wet food is safe at room temperature for up to 1 hour. Canned cat food is shelf-stable and the canning process kills harmful bacteria. However, once exposed to air and your cat’s saliva, bacteria can start to grow.

30 Minutes for Pouches or Tubs

Freshly opened pouches or plastic tubs of wet cat food should not sit out for more than 30 minutes before refrigeration. The FDA recommends refrigerating these foods after serving because they are more perishable. The packaging allows more air contact.

Why You Shouldn’t Let Wet Cat Food Sit Out

There are a few important reasons why allowing wet cat food to sit out is risky:

  • Bacteria grows rapidly at room temperature
  • Salmonella and E. coli risk from contaminated food
  • Foodborne illnesses can be very dangerous for cats
  • Food loses nutritional value when left out

Bacteria Growth

One of the biggest risks is rapid bacteria growth. Wet cat food contains moisture, making it an ideal environment for microbes to thrive if left at room temperature for too long. Refrigeration helps slow this growth.

Salmonella and E. coli

Salmonella and E. coli are two types of dangerous bacteria that can contaminate pet food and make cats sick. Manufacturers take care to eliminate risks, but once food is exposed, bacteria can start to multiply.

Foodborne Illness

Foodborne illness is extremely dangerous for cats, especially kittens, senior cats, and those with compromised immune systems. Lethargy, vomiting, diarrhea, dehydration, fever, and other issues can arise. In rare cases, it can even be fatal.

Nutritional Value

Over time at room temperature, wet cat food starts losing its nutritional value as the fats and proteins deteriorate. Vitamins like vitamin E and specialized fatty acids degrade. So even if bacteria isn’t an issue, the food quality goes down.

Signs of Spoiled Wet Cat Food

If you notice any of the following signs, throw the wet cat food away immediately:

  • Mold visible
  • Slimy texture
  • Change in color
  • Bad, sour, or rancid smell
  • Expired date on the can or pack

Your nose is a great tool for determining if wet cat food has spoiled while sitting out too long. Trust your senses.

How to Store Wet Cat Food Safely

To minimize risks and keep nutrients intact, store all unused wet cat food in the refrigerator:

  • Refrigerate canned food after serving
  • Refrigerate pouches and plastic tubs after opening
  • Use refrigerated food within 5 days
  • Discard any leftover wet food after feeding
  • Store unopened cans in a cool, dry place
  • Don’t mix fresh wet food with old

Refrigerating After Serving

For canned food, seal the leftover portion in the opened can and refrigerate after your cat finishes eating. Transfer any portion scooped into a bowl back into the can or an airtight container. Refrigerate pouches, tubs, or homemade food immediately after serving.

Use Refrigerated Food Quickly

Only keep refrigerated wet cat food for up to 5 days at most before throwing it away. Continually refrigerating and re-serving wet food allows more bacteria growth over time.

Avoid Mixing Old with Fresh

Never mix older leftover wet food with a freshly opened can or pouch. Always discard leftovers after 5 days and serve fresh.

Can Refrigerated Wet Cat Food Be Safely Re-Served?

It’s best to re-serve refrigerated wet cat food only once or twice. The risks include:

  • Bacteria continues to grow though slowed by fridge
  • Fats can turn rancid during re-refrigeration
  • Nutrients break down over time
  • Potential for mold after several re-servings

If re-serving refrigerated wet food, look for signs of spoilage like mold, smell, texture change, or expiry date. Discard if unsure.

Bacteria Growth Even When Refrigerated

Refrigeration at 40°F (4°C) slows but does not stop bacteria growth. Some hardy pathogens like Listeria can still multiply. Fridge temperatures preserve food but don’t make it 100% sterile.

Fat Rancidity

The omega-3 and omega-6 fatty acids in high-quality cat foods can turn rancid after opening. This leads to an unappealing smell and taste. Repeated refrigeration accelerates this fat breakdown process.

Can I Microwave Leftover Wet Cat Food?

Microwaving is not recommended for wet cat food leftovers. The risks include:

  • Microwaves heat unevenly and create hot spots
  • Nutrients like proteins and vitamins degrade
  • Danger of burns to your cat’s mouth
  • Texture and moisture content changes
  • Unsafe for canned food with metal lids

Uneven Heating and Hot Spots

Microwave ovens do not heat wet foods evenly. There may be scalding hot spots even when the food looks warm. This poses a serious oral burn risk for your cat.

Nutrient Breakdown

Proteins, certain vitamins, and other nutrients are heat sensitive. Microwaving wet cat food degrades the quality, even if bacteria are killed. The food loses nutritional value.

Is It Safe to Freeze Wet Cat Food?

Freezing is a smart way to safely store unused portions of wet cat food for later use. Benefits include:

  • Freezing stops bacteria growth
  • Prevents fats from becoming rancid
  • Retains nutrients longer
  • Lets you buy in bulk and save money

Freezing wet cat food for up to 6 months is considered safe. Make sure to promptly re-refrigerate thawed food and use within 5 days.

Freezing Prevents Spoilage

The freezing process stops bacteria growth and spoilage reactions. This preserves the food’s safety and quality for months if kept frozen, though nutritional value degrades over time.

Buying in Bulk

Stocking up and freezing wet food allows cat owners to take advantage of bulk deals. Large cases of canned cat food or pouches can be portioned out and frozen.

Thaw Safely Before Serving

Thaw frozen wet cat food in the refrigerator, not on the counter. Re-refrigerate promptly after serving and discard any leftovers within 5 days to prevent spoilage.

Can Thawed Wet Cat Food Be Refrozen?

Previously frozen wet cat food should not be re-frozen after thawing. The risks include:

  • Bacteria starts growing once thawed
  • Multiple freezes deteriorate texture
  • Nutritional value drops with repeated freezing
  • Increased risk of freezer burn

Bacteria Growth Resumes

Harmful bacteria like salmonella and listeria are no longer dormant once food is thawed. Refreezing allows microbes to multiply to dangerous levels.

Texture Changes

The freeze/thaw process breaks down the delicate proteins and fibers in wet cat food. Refreezing makes the food mushy and unappealing in texture.

The Best Practices for Cat Wet Food Safety

Follow these tips for handling wet cat food safely:

  • Discard any food after 1 hour sitting out
  • Promptly refrigerate opened cans or pouches
  • Never mix fresh wet food with older leftovers
  • Throw away refrigerated leftovers after 5 days
  • When freezing, portion into icy cube trays
  • Never re-freeze thawed wet cat food
  • Look for signs of spoilage before serving

Use Proper Storage Temperatures

Keep wet cat food at safe temperatures – under 40°F (4°C) in the refrigerator or 0°F (-18°C) in the freezer. Never leave food sitting out at room temperature for an extended period.

Serve Fresh Food Only

Discard leftovers promptly and always replace with a fresh portion. Don’t mix older refrigerated or frozen wet food with new serving. This minimizes bacteria build up.

The Dangers of Using Spoiled Wet Food

Feeding your cat spoiled, moldy, or bacteria-laden wet food can make him dangerously ill. The possible effects include:

  • Vomiting
  • Diarrhea with or without blood
  • Dehydration
  • Abdominal pain
  • Fever
  • Kidney or liver damage
  • Neurological issues in severe cases

Kittens, senior cats, and those with compromised immunity are especially vulnerable. Seek veterinary care immediately if your cat shows these symptoms after eating wet food left out too long.

Foodborne Toxins

Salmonella, E. coli, and mold toxins are examples of harmful compounds that can form in spoiled wet cat food. Ingesting these can poison your cat’s system.

Dehydration Risks

Excessive diarrhea and vomiting leads to fluid loss, dehydration, and dangerous electrolyte imbalances. IV fluids, hospitalization, and intensive treatment may be needed.

Should You Switch to Dry Food for Safety?

Dry kibble avoids many of the risks of wet canned food sitting out. But dry food has downsides too, including:

  • Higher carb content
  • More plant protein instead of animal meat
  • Kidney stress from chronic dehydration
  • Dental issues from lack of chewing
  • Higher calorie density often

A better option than switching totally to dry food is taking precautions with wet food handling and storage. Combine both wet and dry food for best results.

Higher Carbohydrates

Many dry foods contain higher proportions of grains and carbohydrates. This may contribute to obesity and diabetes in some cats. Wet foods often have more protein.

Kidney Issues

The lack of moisture in kibble may stress kidneys over time and lead to dehydration. This may worsen kidney disease.

Tips for Transitioning Your Cat to Refrigerated Wet Food

If your cat is used to having wet food sit out and getting “treat” meals later, re-training her to only eat refrigerated fresh portions may take time. Tips include:

  • Mix in refrigerated with room-temperature food initially
  • Transition to all refrigerated over 2 weeks
  • Stick to scheduled meal times, don’t free-feed
  • Refrigerate brand new unopened cans for consistency
  • Make sure bowls are very clean and fresh

Gradual Transition

Cats dislike abrupt food changes. Mix a bit of chilled wet food with room temperature portions. Over 2 weeks, increase the refrigerated ratio until it’s all cold food.

Schedule Meal Times

Instead of free-feeding wet food, establish set meal times twice a day. After 30 minutes, discard uneaten refrigerated food to motivate your cat to adjust.

Keep Bowls Clean

Use fresh clean bowls at every meal and wash in hot soapy water. This removes any lingering scents that may cause your cat to reject refrigerated food.


How long can an opened can of wet cat food last in the fridge?

An opened can of wet cat food will stay fresh in the fridge for 3 to 5 days. Discard any uneaten portions after this time to prevent spoilage.

Can I freeze single-serve cat food pouches?

It’s fine to freeze unused portions of wet cat food in single-serve pouches. Flatten the pouch to thin out food before freezing. Defrost in refrigerator before feeding.

Should wet cat food bowls be washed every day?

Yes, wash your cat’s wet food bowls with hot soapy water after each meal. Bacteria and old food odors can cling to bowls and put your cat off fresh refrigerated portions.

Is it safe to microwave refrigerated wet cat food?

No, microwaving is risky due to uneven heating and nutrient degradation. Always serve chilled wet cat food immediately from the fridge, or warm it by placing the bowl in hot water for a few minutes.


Wet or canned cat food should never be left sitting out at room temperature for an extended time. Pouches and opened cans should be refrigerated promptly and used within 3 to 5 days. Freezing is best for long-term storage. Follow these wet food safety tips to keep your cat healthy.

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