A routine examination by the Food Safety Authority of Ireland has revealed that of 27 frozen beefburgers analysed, 10 of them contained horse DNA, whilst fully 23 of the products contained pig DNA.

One sample contained 29pc horse meat. That's a lot of horse.
http://www.independent.ie/opinion/analysis/john-mckenna-why-billioneuro-meat-industry-has-to-rein-in-this-horse-scandal-3354628.html