Washington ? The pet food recall expanded further Tuesday to include products made at a Canadian factory recently found to have used an ingredient tainted by an industrial chemical.

Menu Foods previously had recalled only cat and dog food made at its plants in New Jersey and Kansas, saying they were its only facilities to have taken delivery of imported wheat gluten later found contaminated with melamine.

However, Menu Foods discovered Monday that some of the tainted wheat gluten had made it to Canada. It was prompted to account for the ingredient by the U.S. Food and Drug Administration, which told the company that tests had detected the chemical in pet foods made at its Streetsville, Ontario, plant.

Menu spokesman Sam Bornstein said the amount accounted for just 1 percent of the adulterated Chinese wheat gluten purchased by Menu Foods. It was used in pet foods made in December and January.

Among the products covered by the expanded recall is Royal Canin Canada’s Medi-Cal Feline Dissolution Formula canned diet, made by Menu Foods and sold only through veterinarians. A single production lot contained the contaminated wheat gluten, the company said.

“After being repeatedly reassured by Menu Foods, as reinforced by FDA public statements, that none of the contaminated wheat gluten had made its way to Canada, we were completely shocked to learn yesterday that this was not the case,” Xavier Unkovic, Royal Canin Canada’s chief executive officer, said in a statement.

Menu Foods was the first of at least six companies to recall pet food and treats made with the tainted Chinese wheat gluten. It alone has recalled 100 brands of pet foods, sold throughout North America under its private and major labels. It posted Tuesday an updated list of recalled products on its Web site, http:// menufoods.com/recall/.

The FDA has blocked wheat gluten imports from a Chinese company while it investigates how melamine could have contaminated the vegetable protein.