With continued high profile media coverage in the UK of cheap processed beef products being contaminated with horsemeat, comes news that phenylbutazone residues have been found in horses slaughtered in the UK. Between 30 January 2013 and 7 February 2013, of 206 horses slaughtered in the UK, eight tested positive for phenylbutazone of which 6 carcases were exported to France.

http://www.food.gov.uk/news-updates/news/2013/feb/bute-carcasses-results#.URzjEvIXbdc

Widespread DNA testing (up to 2500 tests) of beef products across the EU for horsemeat, and expanded testing (4000 tests) of horse carcases for phenylbutazone is being proposed by the European Commission with the first results to be published on April 15th 2013.