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Lab experiments “terrifying” for animals

The most harmless-seeming lab experiments spark panic in the creatures going through them, according to a new report. But supporters of animal medical research, who say the work saves lives, questioned the findings. 

The report, based on a review of past scientific studies, claims that mice, rabbits, rats, beagles, geese, and other animals all show measurable levels of stress in response to routine laboratory procedures.

These procedures, including blood draws and use of stomach tubes, are “terrifying” for animals, according to a press release announcing the findings. The statement was issued by the Physicians Committee for Responsible Medicine, a Washington, D.C.-based nonprofit group.

Jonathan Balcombe, a research consultant for the group, authored the report finding that physiological stress levels go up among animals undergoing experiments.

Even simple contact with laboratory workers is scary for animals, said Balcombe. “There is no such thing as a humane animal experiment,” he said in the statement. “Fear or panic ensues when the animal is touched or stuck with a needle.”

Balcombe isn’t new to the longstanding debate over whether it is right to use animals in scientific research. He has argued against the use of vivisection, the act of operating on live animals. “Vivisection labs cause animals pain, misery and death, and should be actively opposed,” though not by violence, as some say, he wrote in an April 29, 2004 letter to the Times of London.

But the new findings, according to the committee, are the first time such misery has been shown to befall animals during procedures that have until now been seen as relatively benign.

Balcombe’s full findings are published in the Autumn 2004 issue of the research journal Contemporary Topics in Laboratory Animal Science. The findings are based on an extensive review of the scientific literature by Balcombe, an ethologist, or scientist who studies animal behavior.

A mouse who is picked up and briefly held experiences several physiological reactions, according to the group: As stress-response hormones flood the bloodstream, the mouse exhibits a racing pulse and a spike in blood pressure. These symptoms can persist for up to an hour after each event. Immune response is also affected.

“In rats and mice, the growth of tumors is strongly influenced by how much the animals are handled,” the group’s statement said.

Supporters of medical research that uses animals said they don’t have much faith in Balcombe’s study. “I would be very skeptical of anything that comes out of” Balcombe’s group, since it is also already on record as being anti-vivisection, said Barbara Davies, communications director for RDS, a British organization of scientists who support medical research.

Barbara Rich, a spokeswoman for Americans for Medical Progress, an Alexandria, Virginia-based group, echoed that. “It may be that they came to the conclusion before they did the study,” she warned. Balcombe’s group is closely allied with the radical animal-rights group People for the Ethical Treatment of Animals, she added.

On the other hand, Rich acknowledged, the journal that published the paper is reputable. She said more scientists will have to assess it, especially as it seems to contain some strange conclusions. “One person said to me, ‘if handling animals causes tumors, what does this say about our pets?’”

Balcombe dismissed that objection. “The difference between my pet rats and a rat in a laboratory is my pet rats don’t ever get stuck with needles, have blood drawn or get force-fed a drug,” he said. Lab animals learn to expect bad things, and their fear of handling stems from that, he added; this isn’t the case with pets.

The journal’s editors also expressed reservations about the paper. In an editorial in the same issue of the journal, they wrote that the paper is an  “opinion piece. The literature discussed... is selective in scope and does not include a rigorous review of current methods and studies concerned with detecting or observing effects of stress in laboratory animals. We caution that it is not correct to conclude that stress is equivalent to distress or fear.”

Balcombe objected to the portrayal of his study as selective. He said his review of scientific literature included all past papers that he could find meeting certain clear criteria. None that met these conditions was excluded, he asserted: any study was included if it examined animals’ stress responses to handling and routine experimental procedures. 

Balcombe also called the editorial itself highly unusual for a research journal -- evidence of how controversial the subject of animal research is. “One would have to look far and wide among journals to find an editorial disparaging of the research” published in the same journal, he observed.

Moreover, Balcombe wrote that while it can be argued that stress and fear are different, evidence shows that in this case, stress does correspond to fear. One clue is the fact that animals try to avoid most of these laboratory procedures, he explained. 

The paper focused on three routine procedures: handling, blood collection and force-feeding. Independent of the invasive experiments themselves, these daily routines can cause an animal to experience elevated bloodstream concentrations of substances known to indicate stress: corticosterone, prolactin, glucose, and epinephrine, Balcombe wrote. Impaired immune response has also been recorded in animals after anxiety-producing contact with lab personnel, according to the study.

Balcombe argued that scared animals don’t produce sound scientific findings because their fear leads to distorted experimental results.

“Research on tumor development, immune function, endocrine [hormonal] and cardiovascular disorders, neoplasms [tumors], developmental defects, and psychological phenomena are particularly vulnerable to data being contaminated by animals’ stress effects,” said Balcombe.


World Science. December 30, 2004.

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