- news, features, articles and disease information for the beef industry


Veterinary Residues in Horse Meat, Imported Fish Raise Mild Concerns

24 October 2013

UK - In its 2012 Annual Report, just published, the Veterinary Residues Committee (VRC) reports finding residues in just 97 food samples of the more than 31,000 tested.

Phenylbutazone was found in five samples of horse kidney and concerns were raised that leucomalachite green, which is not permitted in the EU, continues to be found in imported fish from third countries. A relatively high number of thiouracil non-compliant samples from cattle found in 2011 were the result of feeding a diet rich in brassicas such as rapeseed meal.

UK Produce 

In the Statutory Surveillance Scheme 31,612 samples were collected and used for 34,386 analyses. There were 106 residues detected in excess of statutory or other action limits in 97 samples. Of these, 60 were either environmental contaminants or substances which occur naturally in animals. A total of 37 samples (0.1 per cent) contained residues of the pharmacologically active substance(s) for which they were tested.

What were the residues of concern?

Follow-up investigations were carried out and in 17 cases where causes could be established, they showed that the rules for use of the veterinary medicinal product involved had not been fully followed. There was however, no risk to human health.

Another five cases involved the presence of phenylbutazone, a non-steroidal anti-inflammatory drug (NSAID) which is not authorised for use in any food-producing animal. The substance was detected in horse kidney samples tested as part of a NSAID screen, at concentrations of 4.9, 8.2, 12, 49 and 1,200μg/kg, respectively.

What is the significance of the results?

The VRC is reassured that with a very large and wide-ranging programme of surveillance only those five results of concern to consumer health were detected.

Overall, the Statutory Surveillance Scheme results demonstrate that when used as directed, veterinary medicinal products did not result in residues of human health concern in 2012, and that consumers can continue to have confidence in purchasing UK produced foodstuffs of animal origin.

Imported produce 

In the Non-Statutory Scheme 823 samples were collected and 1,811 analyses carried out. No residues have been detected above the Maximum Residue Limit or Action Level in the 2012 programme.

What were the residues of concern?

No non-compliant residues were confirmed in imported food samples for 2012, although two fish samples contained residues of leucomalachite green at concentrations of 0.59μg/kg and 1.3μg/kg respectively. These were below the Minimum Required Performance Limit (MRPL) of 2μg/kg (for the sum of malachite green and leucomalachite green).

What is the significance of the results?

Residues of substances not authorised for use in the EU – notably leucomalachite green - continue to be found in imported fish from third countries, which is of concern to the VRC. The Committee holds the view that surveillance of imported foods for residues of medicines used in countries outside of the EU must be maintained, and coordination improved, to strengthen Non-Statutory Surveillance results with results from other sources.

Follow-up action in 2012

A follow-up study was carried out into two non-compliant samples of honey from New Zealand found under the surveillance programme in 2011.

The samples contained residues of semicarbazide (SEM) which is used as a marker for detecting nitrofuran antibacterials. However, further tests by the New Zealand Ministry for Primary Industries could not identify a synthetic source for the substance and it was concluded that the residues occurred naturally.

Key issues in 2012


Surveillance this year detect ed phenylbutazone in five samples of horse kidney. Where it was possible to establish the source of the residues, the follow-up investigations revealed poor practice and a general lack of awareness of the systems in place to ensure that horses treated with phenylbutazone do not enter the food chain

Low numbers of non-compliant samples in Statutory Surveillance Scheme The number of non-compliant samples that are likely to have resulted from the use of veterinary medicines in 2012 remains low at 37 (0.1 per cent) – whilst higher than 2011 (16; 0.05 per cent) it is much lower than in previous years (there were 63; 0.2 per cent in 2010) and the sampling rates in these three years were very similar.

Naturally occurring unauthorised substances

Surveillance of imported food Low-level residues of some banned substances are regularly found in the Statutory Surveillance programme. The very sensitive analytical methods now used in surveillance can mean that a residue sample tests non-compliant at a level of 1μg/kg. Even if the levels detected are extremely low, detection of such residues triggers the need for follow-up investigations.

From these investigations it is often concluded that the residues did not come from misuse of veterinary medicines and therefore were misleading non-compliant results. It should also be stressed that the residue levels being found do not pose a health risk to humans. Two examples are given below.

In the EU it is illegal to administer to food-producing animals for growth promotion, beta-agonists and substances which have a hormonal or thyrostatic action. However, several of the steroidal hormones can occur naturally in farm animals at very low levels. Also, for example, accidental contamination of urine with faeces during the sampling process can result in the hormone alpha-boldenone being detected. Hormones also occur as a result of the tested animals being pregnant and although attempts are made to avoid testing pregnant animals, it does occasionally happen.

In 2011, the Committee noted a relatively high number of thiouracil non-compliant samples from cattle which can result when they are fed a diet rich in brassica. The Committee asked the Advisory Committee on Animal Feedingstuffs (ACAF) if they were aware of any changes in feeding practices which might account for this. ACAF advised the Committee that there probably has been a trend for an increase in brassica-rich feed (e.g. rapeseed by-products) and also that environmental conditions and crop variety can influence the concentrations of naturally occurring substances in rape from which thiouracil may be derived.

Surveillance of imported food

The Committee continued to make clear its concerns about the level of testing carried out under the Non-Statutory Surveillance Scheme. It was disappointed to hear that a reduced level of Defra funding would be available for the 2012 programme, but, in spite of tough economic conditions, is pleased with the commitment to fund it at that level for 2013 and 2014, subject to other Defra priorities.

The Committee remained keen on seeing the results of tests on imported foods carried out by other bodies. In particular, it has welcomed seeing summaries of results produced under Defra’s National Monitoring Plan, which is required of all Member States by the EU  Vetchecks Directive to supplement the National Surveillance Scheme results. However the lack of information on testing done by retailers or their suppliers in the area, to ensure due diligence, remains a concern.

Further Reading

You can view the full report by clicking here.

TheCattleSite News Desk

Our Sponsors


Seasonal Picks

Animal Welfare in EPS - 5m Books