PetSmart stores reported that 20 percent of the products, tainted with wheat gluten containing the industrial chemical melamine, haven't been restocked and 10 percent have been discontinued.

Hundreds of products were recalled, many made by Menu Foods, USA Today reported.

PetSmart and Petco, the nation's No. 2 pet merchandise chain, say many customers have switched to dry foods for their pets, although wet and dry foods were involved in the recall.

A USA Today/Gallup Poll involving 574 pet owners showed that 30 percent of those surveyed felt less confidence in the pet food industry after the recalls; 46 percent felt more confidence.

Pet food consultant Greg Aldrich told the newspaper more safety measures are in place.

"It doesn't mean something couldn't slip through in the future but it's a lot less likely," he said.