Propylene Glycol and Cats

Proplyene Glycol is an additive that is present in many dog foods to help with moisture content. In dog food it is an acceptable ingredient that the FDA considers as "generally safe". If propylene glycol was present in high levels in dog food it could be toxic, however.

Propylene Glycol is used in food to accomplish several things:

• To absorb extra water and help keep food moist.
• As a solvent for colors and flavors in the food.

Why is propylene glycol not used in cat food?

While dogs and humans can tolerate small amounts of propylene glycol in their diet, cats cannot. Cats are extremely sensitive to this chemical!

Small amounts of propylene glycol ingestion in cats can cause something called Heinz body anemia. This is the same type of problem that happens when a cat ingests too much onion or garlic. Here is a simple view of what a Heinz body is:

The extra little dot on the red blood cell membrane is a clump of protein. We are not exactly sure why Heinz bodies on red blood cells cause anemia¹. But, it is believed that a red blood cell containing Heinz bodies is much more fragile than a regular red blood cell and therefore, can be easily destroyed within the body.

As more and more toxin is absorbed, the body makes more abnormal red blood cells. If too many red blood cells get destroyed, then the result is anemia, which means that the red blood cell level is too low. If anemia gets severe enough it can be life threatening.

A study² done in 1992 found that the more propylene glycol that is in a cat's food, the more red blood cell damage there is.

As a result, in 1996, guidelines were changed so that no propylene glycol at all was allowed in cat food³.

Related

Chicken Jerky problems in dogs: Some brands of chicken jerky were found to have undeclared propylene glycol.
VitaKitty Recall because of propylene glycol in cat food.

In most cases, once the toxin (i.e. propylene glycol) is removed from the pet's diet, then the body can start to make new, healthy red blood cells again and the pet can return to a completely healthy state.

References

1. Erythrocyte pathology and mechanisms of Heinz body-mediated hemolysis in cats.

2. Hematological alterations in kittens induced by 6 and 12% dietary propylene glycol.

3. FDA - Pet Food labels - general.