Does cat food go off? For me, the question is superfluous because in my experience domestic cats won’t usually eat wet cat food unless it is fresh out of the can or pouch. For the end customer – the pet – the food has gone off within 20 minutes even though it has no where near gone off in a genuine sense. This won’t apply to all cats at all times, however. Even my cat goes back sometimes to eat the leftovers.
Domestic cats normally like it fresh. It is about the smell. They decide whether to eat it on the smell of the food. After a few hours it smells different and it is that difference which makes the difference if you see what I mean.
Based entirely on personal experience, in normal room temperature, wet cat food goes totally off i.e. mould starts to grow on it, after about five days. It varies a lot but it has to be days old before you see mould.
As I said my cat rejects wet cat food after it has been in the dish for a short time. A cat who visits, in contrast, eats whatever is in the dish even if it has been there a couple of days. It depends how hungry the cat is.
I contacted a pet food manufacturer once to ask if there are preservative in their pet food. They said no. The manufacturers would say that wet cat food in the bowl goes off after about 4 hours at ambient temperatures. But opened cans can be stored refrigerated for around five days. My cat would not eat it though so I don’t store it in the fridge. As I said it has to be right out of the pouch.
Also you obviously have to differentiate between wet and dry cat food. You’d think that dry cat food could never go off but it does. Although wet and dry have similar expire dates if kept in an unopened pouch or plastic bag (about 18 months). Dry cat food in the bowl lasts much longer which is why it is so popular and why it the cause of obesity in some households. It is used for free-feeding and left in the bowl for as long as it takes to be eaten.
In fact Hills say:
Dry food can be left in your cat or dog’s bowl indefinitely if the bowl is kept in an area that is cool, dry, out of direct sunlight and not subject to contamination by insects and vermin. However, we recommend that your cat or dog’s food bowl is washed and filled fresh each day.
There you are: dry cat food will last indefinitely in the bowl under the right conditions. They make a slightly contradictory statement on their website. They say that unopened dry cat food should be thrown out after the expire date.
Storage temperatures are important. Above 38 degrees Celsius the vitamins degrade and the fats become rancid in an unopened bag. Cool and dry is the rule.
SOME STUFF ABOUT DRY CAT FOOD: