Researchers Face Criminal Charges for Giving Sheep the Bends

If it’s rats being tested for the bends, that’s one thing. If it’s sheep being tested, the researchers doing it could go to jail. That’s what nine staffers at the University of Wisconsin-Madison face. They could be jailed or pay heavy fines for carrying out decompression experiments on sheep in hyperbaric chambers for the U.S. Navy. The testing was done to gain more information about DCS, but in the extreme conditions used by researchers to invoke DCS, the sheep can experience severe pain in various parts of their bodies, and death.

The researchers presented their latest findings at the Undersea & Hyperbaric Medical Society’s annual meeting in June. Over the years, they’ve studied oxygen pre-breathing as a means to reduce or prevent DCS. In this study, they looked at the effect of interrupting oxygen pre-breathes with an air break. Ten adult sheep were put in a decompression chamber at 60 feet for 24 hours, given an oxygen pre-breathe for three hours, followed by a “dropout decompression” at 30 feet per minute to surface. Another 10 sheep underwent the same procedure with a one-hour air break before decompression. After surfacing, all sheep were observed for signs of DCS. A month later, bone scans and IV injections look for effects of bone injuries. While all sheep survived the decompression, all 10 in the air break group got bends in their limbs within 10 minutes of surfacing, and three of those developed respiratory DCS. In the group without an air break, eight sheep got the bends within two hours of surfacing. Whether the sheep died or were killed afterwards isn’t mentioned in the paper but the researchers’ last step was to perform necropsies of the sheep, and they found severe bone injuries.

Two animal rights groups, PETA and the Alliance for Animals, led the charge against the researchers, filing a suit after they discovered that Wisconsin has a law banning the killing of animals through decompression. In June, Judge Amy Smith backed their claims. She concluded that the researchers “intentionally or negligently violated Wisconsin law,” and appointed a special prosecutor to determine whether they should face criminal charges. Smith dismissed the university’s defense that the research project was exempt from the law, noting that numerous sheep have died in its experiments since 1988 and the researchers likely “knew some sheep would die from decompression, or that there was a substantial and unreasonable risk of such a death.”

The university said it stopped doing the experiments when they became aware that they may be violating state law, but it’s working to get the law changed so they can continue doing the decompression experiments.

- - Vanessa Richardson