Bute found in Asda Smart Price Corned Beef SUPERMARKET giant Asda recalled all tins of corned beef from its budget range tonight after the government's food standards watchdog said traces of a painkiller used on horses has been found in some batches. The Food Standards Agency (FSA) said "very low levels" of the veterinary medicine phenylbutazone, known as bute, had been found in 340g tins of its Smart Price Corned Beef. Customers who have bought the tins, with any date code, have been urged not to eat the corned beef but to return it to the supermarket. The product is the first that has tested positive for bute since an investigation into horse meat contamination began in January 2013. In the UK, horse carcasses must have a negative bute test before they are allowed to enter the food chain. In a statement, the FSA said: "Anyone who has Asda Smart Price Corned Beef should not eat it, but return it to the nearest Asda store for a full refund. Animals treated with bute should not enter the food chain as the drug may pose a risk to human health. However, even if people have eaten products that contain contaminated horse meat, the risk of damage to health is very low. Asda, which has 53 stores in Scotland, withdrew the product on 8 March after it was found to contain more than 1 per cent horse DNA. Bute was detected in samples, at the level of four parts per billion, when further tests were carried out. The FSA said no other Asda products are thought to be affected and that customers who bought the corned beef should contact the supermarket for a refund. An Asda spokesman said last night: "We have taken an extremely cautious approach since the very beginning and have carried out more than 700 tests, moving swiftly to remove any products from our shelves whenever we've had the smallest concerns. In March 2013 we withdrew tinned Smart Price Corned Beef after receiving a positive test for horse DNA above the one per cent trace level set by the Food Standards Agency. Today, tests on further batches have shown a positive result for very low levels of horse medication called phenylbutazone, also known as bute, at four parts per billion. The FSA has reassured us that the quantities we've found pose a low risk to human health. In a statement on its website, Asda said it was also recalling tins of Chosen By You corned beef. Professor Dame Sally Davies, England's Chief Medical Officer, had previously said that horsemeat containing bute presented a "very low risk to human health." She said: "Phenylbutazone, known as bute, is a commonly used medicine in horses. It is also prescribed to some patients who are suffering from a severe form of arthritis. The levels of bute that have previously been found in horse carcasses mean that a person would have to eat 500 to 600 100 per cent horsemeat burgers a day to get close to consuming a human's daily dose. And it passes through the system fairly quickly, so it is unlikely to build up in our bodies. In patients who have been taking phenylbutazone as a medicine, there can be serious side-effects, but these are rare. It is extremely unlikely that anyone who has eaten horsemeat containing bute will experience one of these side-effects. Asda's Smart Price Corned Beef is manufactured by the French supplier Toupnot. The horsemeat scandal erupted in January, when testing in Ireland revealed that some beef products also contained equine DNA. In February, the French agriculture minister said meat from three horse carcasses contaminated with bute had entered the human food chain in France, but added that there was no public health risk. The affected carcasses were from horses that had been slaughtered in Britain and exported to France.