In 2011, 3.79 million experiments were carried out on animals – 68,100 more procedures than in 2010. This follows a rise of 3 per cent the previous year and an upward trend since 2000.
The bulk of the procedures – 71 per cent – involved mice; just 2 per cent involved mammals.
The big rise was in the use of fish. The number involving them increased by 72,959, or 15 per cent, said Judy MacArthur Clarke, head of the Animals in Science Regulation Unit within the Home Office.
At a briefing in London on 10 July, she said that the fish rise reflected efforts to carry out research on animals with lower brain sensitivity.
The figures also show rises of 37 per cent in the use of pigs and 26 per cent in the use of cats, both from a relatively low base. All the cats were used in research for their own benefit, such as feline nutrition.
Meanwhile, the number of monkeys used in procedures dropped by 41 per cent for species from the New World (Central and South America) and 68 per cent for those from the Old World (Africa and Asia). However, the data were unable to show if this was a result of such research moving overseas.
Dr MacArthur Clarke stressed that the statistics did not show where efforts have been made to reduce animal suffering in experiments or if numbers would have been higher were it not for the development of alternatives.
Changes to monitoring to be brought in under European Union law in 2014 will give more detail on the severity of procedures, she added.
Mark Prescott, head of research management and communications at the National Centre for the Replacement, Refinement and Reduction of Animals in Research, told the briefing that “demand for animal use is outstripping the pace at which we can develop alternatives”.
“We need greater investment and efforts in this area. We could do very much more if we had a larger budget, without doubt,” he said.
Humane Society International UK said that it was “extremely disappointed” with the figures announced.
The continuing rise was attributed by Troy Seidle, director of research and toxicology at the society, to a “decade of over-reliance on animal experiments”. He added that the figures demonstrated “the government’s failure to grasp the sea change in attitude needed to escape the scientific cul-de-sac of animal experimentation”.
Martin Walsh, head of policy at the ASRU, told Times Higher Education that although international comparisons were difficult, the UK generally used proportionately fewer animals in research than the US, and was about on par with France and Germany.
The Home Office’s ASRU annual report 2011 also says that inspectors found 39 cases of animal-use regulations being infringed last year.
These ranged from making errors in labelling and exceeding what was technically permitted under licences to mistakes or inadequate facilities that resulted in severe harm to animals.