It did not enter the food chain and investigations into the origin of the meat product are continuing.

BBC: Burgers

Meat from any that are not tested may not enter the food chain.

CNN: Beef sales slump after EU BSE scare

While the FSA insists there is a low risk to health, bute is not allowed to enter the food chain.

BBC: Horsemeat scandal: Birds Eye withdraws UK ready meals

In the UK, horse carcasses must have a negative bute test before they are allowed to enter the food chain.

BBC: Veterinary drug found in Asda budget corned beef

Phenylbutazone, also known as bute, is not allowed to enter the food chain because it can pose a risk to humans.

CNN: Ikea finds horse meat in Russian hotdogs

Animals treated with bute are not allowed to enter the food chain because the drug could pose a risk to human health.

BBC: Horsemeat scandal to be reviewed, government announces

Meat from animals treated with phenylbutazone is not allowed to enter the food chain as it may pose a risk to human health.

CNN: UK beef under microscope as horsemeat found in lasagna

The major worry with such deceptions is that horses that have been treated with phenylbutazone - or "bute" - could enter the food chain.

BBC: Science & Environment

Bill Harper, chairman of the National Beef Association south-west region, spoke earlier of his fears that dioxins could enter the food chain through animals.

BBC: Pyre health risk warning

The FSA has asked Findus to test their contaminated beef lasagne for the veterinary drug phenylbutazone as animals treated with "bute" are not allowed to enter the food chain.

BBC: Horsemeat scandal: Beef products 'pose no health risk'

While the drug isn't allowed to enter the food chain in the U.K., British authorities said the risk to those people who may have eaten meat containing it is very low.

WSJ: U.K. Arrests Men in Horse-Meat Probe

Beginning January 30, the Food Standards Agency ordered 100% testing of horse carcasses, and, as of this week, their meat will not be allowed to enter the food chain until the all-clear has been given.

CNN: French investigate source of horse meat labeled as beef

"In January 2012, Defra and the FSA increased checks on horse passports, meaning every horse was checked twice, and from last week no horse can enter the food chain until it is confirmed to be free of bute, " they said.

BBC: Iceland boss blames councils over 'poor meat quality'

That means 9 million potential untraceable and unmonitored animals that could enter the food supply chain either here or abroad.

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Bute is not allowed to enter the human food chain.

CNN: French investigate source of horse meat labeled as beef