Dr Katy Taylor and colleagues from the BUAV and Dr Hadwen Trust for Humane Research very recently published the most accurate estimate of global laboratory animal use, to date (1). They estimated that 58,339,972 living non-human vertebrates were subjected to fundamental or medically-applied biomedical research, toxicity testing, or educational use, in 179 countries (including all with a human population > 200,000), in 2005. Taylor and colleagues also provided an extremely useful ranking table estimating laboratory animal use figures in most of these countries. The largest users were the US, followed by Japan and Great Britain.

By using weighted means to average data from countries where it existed, I’ve just published an estimate that 68,607,807 additional animals may have been killed for the provision of experimental tissues, used to maintain established genetically-modified strains, or bred for laboratory use but killed as surplus to requirements (2). Such animal use also raises serious bioethical concerns. This results in a grand total of almost 127 million non-human vertebrates used worldwide in 2005.

Further details of these studies are available at:


To date, these remain the most accurate estimations of global laboratory animal use, significantly updating previous estimations which have been based on variable expert opinions, or very limited surveys.

Despite their magnitude, it appears likely that these estimates remain highly conservative. As identified by Taylor and colleagues, for example, their estimate of 17.3 million living vertebrates used within the US is very significantly less than a 2000 US Animal Plant Health Inspection Service estimate of 31–156 million, based on extrapolation from the results of a survey of only 50 of 2,000 research institutions (3). Furthermore, these estimates exclude several other categories of concern, such as some invertebrate species now understood to have advanced capacity for suffering, including certain cephalopods, and studies on advanced fetal developmental stages.

I hope this information will be useful to those working on animal experimentation.

With regards,

Andrew Knight

Animal Consultants International



1. Taylor, K., Gordon, N., Langley, G. & Higgins, W. (2008). Estimates for worldwide laboratory animal use in 2005. ATLA 36, 327–342.

2. Knight A. 127 million non-human vertebrates used worldwide for scientific purposes in 2005. ATLA: Alternatives to Laboratory Animals 2008; 36(5): 494-496.

3. USDA (2000). Rats, mice and birds database: researchers, breeders, transporters, and exhibitors. A database prepared by the federal Research Division, Library of Congress under an Interagency Agreement with the United States Department of Agriculture’s Animal Plant Health Inspection Service, August 2000. Washington, DC, USA: United States Department of Agriculture: Animal and Plant Health Inspection Service. Available at: http://www.aphis.usda.gov/ac/locreport.html  (Accessed 21.02.08).