The US Food and Drug Administration has started to test petfood for Salmonella contamination to prevent pet owners from getting sick by handling the petfood.

In October 2011, FDA investigators began taking samples of dry petfood, pet treats and pet diet supplements from distributors, wholesalers and retailers such as PetSmart, Petco, WalMart, Costco, Sam's Club and Target.

In a memo, FDA said it is "particularly concerned about Salmonella being transmitted to humans through petfoods, pet treats and supplements for pets that are intended to be fed to animals in homes, where they are likely to be directly handled or ingested by humans."

While people usually get Salmonella poisoning by eating contaminated food, according to the Centers for Disease Control and Prevention, they can also become sickened by handling a product that is contaminated with these germs, like petfood or treats.