Hi NikL
Those are the red top tabloids - but although they'll print and feature 'sensational' stories, often in more simplistic black and white terms - it doesn't mean that the actual facts behind those stories are inaccurate.
In this instance, The Daily Mirror, decided to give the story maximum coverage with a 'campaigning' front page backed up by a double page spread inside - in contrast to other newspapers, who seem to have responded with their own stories on their websites:
http://www.dailymail.co.uk/news/article-4159146/Inside-vampire-horse-farm.html
http://www.thetimes.co.uk/article/horse-blood-hormone-used-in-british-bacon-and-sausage-vhkt50xtn
Remember, this is not a new story:
BUT it is The Daily Mirror that has given it wide-spread national coverage.
The Daily Mirror's 'saving grace' is that, in contrast to the majority of the UK national press, it is traditionally a 'working class labour/left-leaning' mass market newspaper, and is probably thought of as the most reliable of the red-tops - partly due to it's background of providing a print outlet for such investigative journalism of noted reporters such as Paul Foot and John Pilger.
On the 'quality' newspaper side, The Guardian (and it's sunday sister title The Observer) are also liberal/left-leaning. Although things have changed now regarding newspaper buying - from experience of visiting JW friends etc, it used to be that, particularly on Sundays, that households would buy BOTH The Observer and The Sunday Mirror. - remember that, although less so nowadays - in broadbrush terms, in the UK, the daily newspaper you read depends on your politics, not on where you live.