On February 14 the Food Standards Agency (FSA) released a statement that it had detected the presence of phenylbutazone (bute) in horses slaughtered in the UK.
They tested a total of 206 horse carcasses between January 30 and February 7 2013. Of these, eight tested positive for the drug.
Of these eight:
The FSA is gathering information on the six carcasses sent to France and will work with the French authorities to trace them.
The official advice that eating horsemeat contaminated with phenylbutazone poses little risk to health remains unchanged. Though as a precaution every effort is being taken to determine the extent of the potential contamination.
Further industry tests results are expected today (February 15).
Concerns have been raised about the safety of horsemeat in the wake of the contaminated beef scandal. The Daily Mail asks 'Is horsemeat harmful after all?', while The Guardian states that 'Contaminated horsemeat could harm health, warns environment secretary.'
Horsemeat has been confirmed to have been present in several products labelled and sold as 'beef'. Horsemeat in itself is not a health risk, with some commentators arguing it is actually healthier than beef as it contains less fat.
The main worry is that as the horsemeat has been illegally introduced into the food chain, it might not comply with the standards normally applied to food for human consumption.
In particular, there are concerns that the horses may have been treated with the veterinary drug phenylbutazone, which is not permitted in the human food chain, and is only used in humans as a treatment for ankylosing spondylitis for which other treatments have been deemed unsuitable.
Phenylbutazone – which was used to treat arthritis and gout – was withdrawn from use in humans after evidence emerged that it could cause serious side effects. The chances of these side effects occurring was very rare (estimated to be one in 30,000), but as there are safer drugs that are just as effective drug regulators decided to err on the side of caution.
It should be stressed there is currently no evidence that phenylbutazone is present in any of the products identified as containing horsemeat, and further tests have been ordered to confirm this.
The Chief Medical Officer, Dame Sally Davies, said: "It's understandable that people will be concerned, but it is important to emphasise that even if [phenylbutazone] is found to be present at low levels, there is a very low risk indeed that it would cause any harm to health."
The Food Standards Agency (FSA) has ordered food businesses to conduct tests to determine what type of meat is present in all products labelled as beef products, such as beefburgers, meatballs and lasagne. Horsemeat itself is not a health risk and is eaten in many countries worldwide.
The FSA has also ordered Findus to test whether its beef lasagne, which has already been found to contain horsemeat, contains phenylbutazone.
Chief Medical Officer Dame Sally Davies said: "We are working closely with the FSA and DEFRA to investigate how horsemeat got into the UK food chain."
Phenylbutazone – also known as 'bute' – is a non-steroidal anti-inflammatory drug (NSAID). In the UK it is authorised for the treatment for certain musculoskeletal disorders and arthritic diseases in dogs and horses.
It was originally developed for the treatment of rheumatoid arthritis and gout in humans.
Phenylbutazone has had its use as a drug for humans limited to very specific cases. When it was more widely used to treat people it was found that about one in 30,000 people suffered a serious side effect.
Some patients experienced severe toxic reactions. In particular, the drug was linked to a rare condition called aplastic anaemia, where bone marrow stops producing new blood cells to replace existing cells, which can be fatal if left untreated.
As phenylbutazone can cause severe toxic reactions, it was banned from use in food-producing animals as it was unclear whether there is a 'safe' level of the drug.
The FSA states that it doesn't currently advise people to stop eating meat products in general. However, anyone who has Findus lasagne in their freezer should return it to the shop they bought it from as a precaution. The Findus lasagne has been withdrawn from sale.
Tesco frozen beefburgers, Aldi Today's Special frozen beef lasagne and Aldi Today's Special frozen spaghetti bolognese have also been withdrawn, and people who have bought them should return them to the shops as a precaution.
The FSA says that there is no reason to think there is a food safety problem at the moment.
If the horses were given the drug, phenylbutazone is only likely to be present in the contaminated meat products in very low concentrations. These levels are likely to be much lower than those previously used to treat humans. This suggests that any risk to health is likely to be very low.
Chief Medical Officer Dame Sally Davies released a statement today that said: "We are working closely with the FSA and DEFRA to investigate how horsemeat got into the UK food chain. There is nothing to suggest a safety risk to consumers who may have eaten the products.
"All of the retailers involved so far have removed potentially affected products from their shelves … there are international checks to prevent phenylbutazone from entering the food chain because there is a low risk of serious effects – such as aplastic anaemia – in some people. As such, it presents a limited public health risk and CMO supports the FSA advice that it should be excluded from the food chain.
"There is currently no indication that phenylbutazone – bute – is present in any of the products that have been identified in this country, but the FSA has ordered further tests to confirm this.
"It's understandable that people will be concerned, but it is important to emphasise that even if bute is found to be present at low levels, there is a very low risk indeed that it would cause any harm to health."