LEEDS, England – Asda, a British supermarket chain owned by Wal-Mart, recalled a canned corned beef product after tests revealed traces of phenylbutazone. Animals treated with the veterinary drug are prohibited from the food chain on concerns it may pose a risk to human health.

The company said it pulled Smart Price Corned Beef in March after receiving a positive test for horse meat above the 1 percent threshold set by the Food Standards Agency (FSA). Tests on additional batches of the products were positive for “very low levels” of phenylbutazone, also known as 'bute' at 4 parts per billion. The test results were released on April 9.

“The FSA has reassured us that the quantities we’ve found pose a low risk to human health,” Asda said in a statement on its website. “They say: “Bute is not allowed to enter the food chain; however, even if people have eaten products which contain contaminated horse meat, the risk to health is very low.”

“Although there is a very low health risk, we are recalling this product,” the statement continued. “This simply means that we ask anyone who has tinned Smart Price Corned Beef (340g) in their cupboards at home to bring it back into store for a full refund.”

Phenylbutazone, an anti-inflammatory drug, can be used to treat non-food producing animals, such as dogs and sport horses. But it cannot be used to treat food animals in European Union member states.

“I know our customers will be just as concerned about this news as we are,” said Ade McKeon, the Asda director responsible for the quality of all its private label products. “Even at such a low level, it is totally unacceptable.

“I can reassure our customers that we are working closely with the FSA and our suppliers to deliver a wide ranging and rigorous program of testing, to be sure that the products we sell are exactly what it says on the label.”

In March, the European Commission asked the European Food Safety Authority and the European Medicines Agency to conduct an assessment of the risks of human health from bute in horse meat.