An industrial chemical that led to the nationwide recall of more than 100 brands of cat and dog food has turned up in a second pet food ingredient imported from China.
The discovery expands the monthlong cascade of recalls to include more brands and varieties of pet food and treats tainted by the chemical.
"This has exposed that the safety standards for pet foods are not in place in any significant way, and the kind of drumbeat, day after day, of recalls has shaken consumers' confidence in the pet food industry's adherence to food safety standards," said Wayne Pacelle, chief executive of the Humane Society of the United States.
The chemical, melamine, is believed to have contaminated rice protein concentrate used to make a variety of Natural Balance Pet Foods products for both dogs and cats, the Food and Drug Administration said Wednesday.
The FDA has said there was no evidence so far to suggest any of the rice protein went to companies that make human food, said Michael Rogers, director of of field investigations. But the FDA has not accounted for the full amount of the imported ingredient.
Previously, the chemical was found to contaminate wheat gluten used by at least six other pet food and treat manufacturers.
Both ingredients were imported from China, though by different companies and from different manufacturers.
The FDA on Wednesday began reviewing and sampling all rice protein concentrate imported from China, much as the agency has been doing for wheat gluten, Rogers said.
Natural Balance said it was recalling all its venison and brown rice canned and bagged dog foods, its venison and brown rice dog treats and its venison and green pea dry cat food.
The recalls now include products made by at least seven companies and sold under more than 100 brands.
The Pacoima company said recent laboratory tests showed its recalled products contained melamine. Natural Balance believes the source of the contaminant was rice protein concentrate, which it recently added to the dry venison formulas.
A San Francisco company, Wilbur-Ellis Co., began importing the ingredient in July from a Chinese company, Futian Biology Technology Co., Wilbur-Ellis Chief Executive John Thacher said.
It resold the ingredient to five pet food manufacturers, including Diamond Pet Foods Inc. of Meta, Mo. Diamond manufactured the dry dog and cat foods recalled by Natural Balance, Diamond spokesman Jim Fallon said.
Thacher declined to identify the other four customers except to say two tested the ingredient and found no melamine. Wilbur-Ellis had not heard from the other two, both of which received a limited amount of the ingredient, Thacher said.