Bacteria growth on dry vs canned food

[FeebysOwner]

I have read numerous posts about how dry food will 'attract' bacteria faster than canned food. Some have said that is because canned is cooked and therefore more 'stable' - but, they are both cooked during the prep/creation process. I have also read numerous posts on how canned can be left out for hours, but dry - if moistened - cannot because of bacterial growth.

Other than the general 'opposition' by many members about dry food in general - which is NOT what I am asking about - what are the reasons for saying canned food can be left out far longer than dry when moistened?

Thanks!

 

[Azazel]

Here's what Dr. P. has to say about it (from Making Cat Food)

And if mold toxins and bacteria in dry food are not enough to cause us worry, please consider the fact that the fats contained in dry food become rancid over time – even with the preservatives that are added to the food. Heat, oxygen and light are all factors involved in fats becoming rancid. Keeping dry food in the refrigerator will help with the issue of heat but that still leaves the oxidation issue unaddressed.

Dry foods sit in warm warehouses and pet food stores before they even reach our pets’ bowls – promoting rancidity of fats, bacterial growth, mold growth, and toxin formation, and proliferation of storage mites.

At the very least, dry food should be kept in the refrigerator but it is better to just refrain from feeding this type of food.

Here's a study she links to about storage mites found in dry food (eew )

Evaluation of storage mite contamination of commercial dry dog food - PubMed

Storage mites may be considered important allergens in dogs with atopic dermatitis. High sensitization rates to Tyrophagus, Acarus, and Lepidoglyphus species have been reported in atopic dogs, and dry pet food has been suggested as a potential source of storage mite exposure. The aim of the...

www.ncbi.nlm.nih.gov

I think canned may be 'better' in this regard because the food is cooked with water already added in and opened cans are stored in the fridge. When you add room temperature or warm water to something that's already stored in a room temperature environment, the build-up of bacteria is much faster.

 

[She's a witch]

I have no knowledge about this but my intuition tells me it's like with humans' processed dry food (pasta, chips, bread, snacks etc), it needs to be stored in a dry place, because if moisture gets to it, it gets spoiled. And dry cats' food is manufactured to be fed, well, dry hence adding water can cause spoilage (=bacterial growth).

 

[MissClouseau]

I agree with She's a witch. I do not agree with wet food can stay long(er than wet dry though.) I think it depends on the wet food and the environment. Like some cities have more humidity than the others. Also not all wet foods cooked the same amount. That's why there doesn't even have to be taurine added to all wet foods, but there is the need for some as they are cooked in the temperatures that heavily decrease taurine.

 

[Willowy]

Canned food is sterile when you open the can. Of course bacteria starts growing right away, but you're starting from a sterile state.

Dry foods are not in an airtight container, and are not sterile. They get sprayed with animal digest after manufacture. It's not like it's just crawling with harmful bacteria or anything, but you aren't starting with a sterile product.

 

[maggie101]

Lately I have been throwing away a lot of opened cans because I forget to put them in the fridge at night.

 

[Gail Wilson]

If bought the right cat food and looked into the expiry date, then you should not have bacteria growth.

To maintain – don't allow free feeding as leaving this out all day can be why you are having problems :-)

 

[maggie101]

Since the cover/lid is on I shouldn't worry about it