A macaque monkey died in its cage at a Brigham and Women’s Hospital research facility in April, after becoming enmeshed in a chain while playing with a toy designed to enrich the lives of research animals.
The hospital disclosed the death Friday, saying it wanted to call attention to the potential dangers of such toys, which have been linked to deaths and injuries of primates used in research elsewhere.
US Department of Agriculture inspectors visited the Boston facility May 16 and cited the Brigham for violating animal welfare rules in the death of the 3-year-old monkey, but assessed no penalties.
A 2005 study by a nonprofit animal welfare organization, which accredits the Brigham and hundreds of other research facilities, indicates that other primates have died in a similar fashion. But how many research monkeys have been injured or killed by enrichment toys is hard to pinpoint — the Agriculture Department, which regulates animal research facilities, did not return calls seeking comment.
The Brigham monkey death is the fifth in less than two years in a Harvard-affiliated research institution, but the first tied to an animal enrichment toy.
Dr. Barbara Bierer, senior vice president of research at the Brigham, said a researcher discovered the monkey entangled in the chain on April 11, just 15 minutes after the scientist had been working with the monkey. The monkey had been playing with a rubber ball that was suspended from a chain outside its cage.
Bierer said scientists cut down the chain and tried to resuscitate the animal, as did a veterinarian who was called.
“This toy has been used safely in the country for many years,” Bierer said.
“Once this happened, all the enrichment toys were removed from all of the [Brigham] facilities and examined and reintroduced appropriately.”
Bierer said the Brigham immediately notified the Agriculture Department, and during the conversation agency officials said they had heard of similar deaths.
“That’s when we started thinking about the safety controls we have in place,” Bierer said. “We have begun to explore whether we can develop a national agenda on this.”
She said Brigham officials have spoken with their counterparts at Massachusetts General Hospital, another Harvard-affiliated facility, to talk about the standards they use in their research labs for primate toys.
Federal regulations have long required research facilities to provide so-called enhancements in monkey cages to “promote the psychological well-being” of the primates.
Many laboratories have used toys sold specifically for this purpose, such as mirrors and balls suspended from ropes or chains, but there are few safety standards for these products, or federal rules governing their safety, Bierer said.
A 2005 study by Kathryn Bayne, global director of the Association for Assessment and Accreditation of Laboratory Animal Care International, concluded that “not all incidents of harm resulting from [animal enrichment toys] are published, thereby allowing some mistakes to be perpetuated.”
The study also noted that long ropes or chains in animal cages have “been reported to lead occasionally to the death” of research monkeys.
Bierer said Brigham officials decided to speak publicly about the accident weeks before regulators are scheduled to release the results of their investigation because the Brigham wants to spark a national conversation.
“It is important to us to bring this terrible accident to the attention of the public in order that other animal programs might use this as an opportunity to reevaluate the safety of enrichment devices and practices within their own programs,” she said.
The Department of Agriculture has cited another Harvard-affiliated facility, the New England Primate Research Center, for seven incidents since 2010 that have directly endangered the safety or welfare of a monkey. Four of those involved deaths.
In a statement Friday, Harvard Medical School said it had removed all toys similar to the one involved in the Brigham death and made “appropriate alterations” to the toys before placing them back in monkey cages.
“After this event, we reevaluated every single enrichment and made appropriate adjustments,” the statement said.
Kathleen Conlee, vice president for animal research issues at the Humane Society of the United States, an animal protection organization, said she has heard of other primate deaths in research labs linked to enrichment toys.
“It’s horrible to think about an animal hanging himself or strangled by a device,” she said. “It’s unacceptable that this wasn’t assessed properly for safety when the information was out there.”
Conlee said that she was heartened to hear that the Brigham provides enrichments for its research primates but said that too often research facilities do not put enough thought into safety and effectiveness of devices and other means to ensure animal welfare.
“Unfortunately it’s relied upon to kind of stick something up there and think that counts as enrichment and there is not enough thought about whether this meets the psychological needs of the animals,” Conlee said. “We still have a long way to go.”
Kay Lazar can be reached at firstname.lastname@example.org. Follow her on Twitter @GlobeKayLazar.