The number of federally regulated animals used in U.S. biomedical research dropped last year to its lowest level since data collection began in 1972, according to new statistics posted by the U.S. Department of Agriculture (USDA). Approximately 834,000 rabbits, nonhuman primates, and other regulated animals were used in research last year, compared with more than 1.5 million in the early 1970s. The use of these animals has been on a downward trend since 1993, with a 6% decrease from 2013 to 2014. Since USDA first started posting its numbers on its website in 2008, total use has dropped 17%. The figures do not include most mice, rats, birds, and fish, which make up 98% of lab animals but are not covered under the 1966 Animal Welfare Act (AWA).
“It’s a continuation of a long-running trend that’s showing no sign of slowing down—in fact it’s speeding up,” says Tom Holder, the director of Speaking of Research, a U.K.-based organization that supports the use of animals in research. Animal rights activists are “very pleased,” says Alka Chandna, the senior laboratory oversight specialist at People for the Ethical Treatment of Animals (PETA), which opposes the use of animals in research.
The use of nearly every kind of AWA-covered animal dropped from 2013 to 2014. Twelve percent fewer dogs were used from 2013 to 2014 (16% fewer since 2008), 11% fewer rabbits (36% fewer since 2008), 11% fewer Guinea pigs (26% fewer since 2008), and 10% fewer nonhuman primates (19% fewer since 2008). The only animals to see an increase were “all other covered species,” which includes ferrets, squirrels, and some rodents (such as sand rats and deer mice) that are not excluded from the AWA. They saw a 25% bump from 2013 to 2014 and a 45% increase since 2008. Cats also saw an increase from 2008 of 4%, but a decrease of 13% from 2013 to 2014.
A USDA spokesperson says the agency will not speculate on what’s driving the trends, but both Holder and Chandna chalk it up to several factors. Among them: the increasing use of computer modeling and tissue cultures, the outsourcing of animal research to countries like China, and the higher costs and growing logistical challenges of using larger animals like nonhuman primates, which are subject to stricter government oversight than in the past. Chandna also cites changes in public opinion, including a recent Pew Research Center poll that revealed that 50% of Americans now oppose animal research. “These trends reflect shifting societal attitudes,” she says.
But the biggest factor appears to be the increasing use of mice and rats in biomedical research. A PETA study conducted earlier this year found that there has been a 73% rise in the use of these animals in U.S. labs over the past 15 years, obviating the need for other types of animals. “We’ve seen a huge rise in the use of genetically modified mice,” agrees Holder, who notes that the trend of using more of these animals and fewer AWA-regulated animals in the United States mirrors what’s happening in the United Kingdom and the rest of Europe. That’s a good thing, he says, because it’s easier to meet the needs of mice and rats than it is for dogs, cats, and nonhuman primates. “I see this as a positive step for animal welfare.”