Only about 15% of the dog and cat foods recalled are back, says Petco (PETC), the number 2 pet-food chain in the US. PetSmart (PETM), the biggest pet-food chain, also says few products have returned but that the bulk is expected in the next few months. Some products will take longer to return, and some have been discontinued, says Michelle Friedman, PetSmart spokeswoman. The recalled Iams products aren't expected back until next year, she says.

Friedman says Menu Foods' products are taking time to return because the company is crafting and applying new safeguards to prevent problems, including more testing of raw ingredients. Petco also says some brands reformulated products and packaging.

Last March, 60 million cans of cat and dog food have been recalled from US stores after contamination of melamine. Chinese companies used this contaminant to boost the protein level of wheat gluten before they shipped it to North America.