If you thought only food for humans was susceptible to salmonella, think again.

The FDA has announced they are investigating pet food in an effort to stem salmonella contamination after concerns owners were becoming ill.

Salmonella could be transferred from pet foods and treats to humans. Pets too can become ill from eating tainted food.

Major retailers like PetSmart, PetCo, Wal-Mart, Costco, Sam's Club and Target are part of the FDA's test pool, and a range of pet foods are being tested -- from cats and dogs to reptiles, birds and rodents.

The FDA is warning pet owners to always wash their hands after handling pet products and keep small children away from pet food and dishes.

Read More:

• Pet Food Added to Salmonella Risks (Wall Street Journal)
• FY 2012 Nationwide Assignment Memorandum (FDA)