The third pet food company since late last week has added its name to the pet food recall list, out of fear that contaminated wheat gluten may have tainted its products.

San Francisco-based Del Monte Pet Products is voluntarily recalling Jerky Treats Beef Flavour Dog Snacks, Gravy Train Beef Sticks Dog Snacks and Pounce Meaty Morsels Moist Chicken Flavor Cat Treats.

It was not clear whether the recall would affect any of the products sold in Canada.

Del Monte's announcement immediately follows the weekend recall of one of the best-known brands of dog food, Purina. The company pulled its Alpo Prime Cuts in Gravy product from U.S. store shelves.

Both companies have said that the wheat gluten supplied to them from a Chinese plant contained melamine — a chemical used in fertilizers in Asia and to make plastics and laminates.

Meanwhile, a Chinese company named by the U.S. Food and Drug Administration as a source of the wheat gluten said it was conducting its own investigation.

A spokesman for Xuzhou Anying Biologic Technology Development Company Ltd. said the company did not manufacture the gluten but had instead purchased the ingredient from an outside source. The FDA on Friday announced it is blocking all imports of wheat gluten from the company.

Hill's Pet Nutrition said late Friday its Prescription Diet m/d Feline dry cat food included the tainted wheat gluten. The FDA said the source was the same company. Hill's, a division of Colgate-Palmolive Co., is so far the only company to recall any dry pet food.

The cat food in question is sold in both Canada and the United States.

Last month, Ontario-based Menu Foods recalled 60 million containers of its "cuts and gravy" style wet pet foods, sold under nearly 100 store labels and major brands across North America.

The FDA traced the problem to melamine after pet owners grew concerned about apparent kidney failure in their cats and dogs. There have been 16 confirmed cases of animals dying in the U.S. after eating Menu Foods products.

With files from the Canadian Press