Menu Foods Inc., the Canadian manufacturer that has recalled more than 5,000 products due to suspected contamination by the toxin melamine, recalled an additional dog food on April 17.

Menu recalled Natural Life Vegetarian 13.2 ounce canned dog food with the date “Nov/22/09” and product code 12344-07114.

The U.S. Food and Drug Administration continues to investigate the recall of pet food products suspected in the deaths and illnesses of potentially hundreds of animals, said Stephen Sundlof, DVM, the agency’s top veterinarian.

Although the FDA suspects that wheat gluten contaminated by melamine, a synthetic plastic used in dishware and some Asian fertilizers, is related to the problem, it has not confirmed that it is causing the animal illnesses.

“FDA is not 100 percent certain that melamine, a relatively nontoxic substance, is the cause of the spate of pet illnesses and deaths,” the FDA said in a statement. “Although some studies have shown a toxic effect of melamine in rodents, research is scarce on melamine’s effect on cats and dogs.”

Adding to the confusion, Natural Balance of Pacoima, Calif., recalled all its wheat-free Venison dog products and its dry Venison cat food on April 17.

The company confirmed that melamine was present in some of its cat and dog food, which might have resulted in kidney failure in cats and dogs that ate the affected products. It suspected melamine was attached to its rice protein concentrate ingredient.

A complete list of recalled dog food products can been seen at http://www.menufoods.com/recall/product_dog.html, and a full list of recalled cat food products is at http://www.menufoods.com/recall/product_cat.html.

For all DogChannel coverage of the ongoing dog food recall, visit www.dogchannel.com/dog-news/dog-food-recall-updates.aspx.