Animals were used 226,000 times in the testing of human and veterinary medicines, medical devices and other health products in Ireland last year, an almost 20% drop from 2013.
According to figures from the Health Products Regulatory Authority (HPRA), mice were the most commonly used animals in such experiments, accounting for almost 90% of the total.
10,465 rats were also used for in experiments, along with 3,153 cattle, 2,107 guinea-pigs, 1,765 sheep, 1,539 rabbits and 698 pigs.
Ferrets, birds, fish, fowl, dogs, cats, horses, donkeys, goats and other mammals and fish were also utilised, but in smaller numbers.
Almost 1% of animals underwent non-recovery procedures, where they were euthanised at the end of a procedure performed entirely under anaesthesia.
40% experienced severe procedures and therefore were not legally allowed to be used for any further procedures. Of those, 98.5% were mice.
The figures have been collated by the HPRA since 2013, when an EU Directive which aims to protect animals used for scientific purposes came into existence.
According to the HPRA, the legislation is among the most advanced pieces of law concerning animal welfare in the world, with the restrictions and standards set by it expected to enhance animal welfare and ensure animals are only used when their use is strongly justified.
The directive is governed by three principles of replacing animals with alternative forms of testing where possible, reducing the overall numbers used and refinement of the methods used to make them as humane as possible.
The most common use of animals in experiments was for the pre-clinical testing of medicines or safety testing.
Translational and applied research, where scientists try to convert basic findings made in-vitro or in computer models into animal models was the next most common.
Of the basic research experiments involving animals, 58% were in the area of immunology, with 14% focused on nervous system research and 8% on the gastrointestinal system and liver.
8,961 genetically modified animals were used in procedures, representing 4% of the total number of animals used, with 94% of that number not showing any impairment to their well-being.
95% of all the animals were born in the EU.
According to the HPRA, while the complete replacement of animal studies is the ultimate goal of the directive, it is currently not possible as non-animal research methods are often not suitable for probing certain biological processes.
The HPRA is responsible for regulating the breeders and suppliers of the animals, places where procedures are performed, projects that use animals and for the training of those carrying out the procedures.
Each establishment carrying out experiments on animals here was inspected at least once last year, the HPRA says, and every application for permission evaluated independently.
