Tickling Rats Reduces Stress of Injections
A new study, published in Applied Animal Behaviour Science, found that rats shows less stress when tickled before given an injection. This finding could help refine laboratory animal care standards and improve the quality and validity of data collected from animals used in biomedical research.
Past studies have found that rats emit ultrasonic chirps when they played with each other, indicating a positive emotional staff. And, in 2000, scientists from Bowling Green State University found that rats are ticklish, and often emit these same ultrasonic chirps when tickled. Additionally, the ticklish rats played more, according to an article in Nature World News.
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"When I first started giving injections to rats, it was a stressful event for both myself and the rats. I thought there had to be a better way to do it. I searched the literature and found some information about handling and habituation but I also found papers about tickling, a handling technique that mimics the rat social play behavior. I started wondering if this technique could be integrated in medical/experimental procedures done with rats. So, I devised an experiment to test it," Sylvie Cloutier, Ph.D., from Washington State University told ALN exclusively.
The latest study found that tickling can be a powerful tool in preventing stress during medical procedures. The researchers, from Washington State University, divided rats into three groups and gave them saline injections once daily for ten days. One of the groups was tickled before given a saline injection, another afterwards. The third group was just given the injection. The researchers compared the levels of discomfort shown by each rat during the procedure, measuring how much they fought their restraints and how frequently they vocalized discomfort.
"When the timing of tickling was compared, the results show that when provided immediately before the procedure, tickling appears to induce a positive affective state in rats allowing them to associate the procedure with playful interactions with the experimenter. Thus, the results suggest that tickling, a positive handling technique, can be used to induce a positive affective state in the rats and ease their exposure to otherwise stressful events such as handling and medical procedures and, thus, minimize the distress generated by these procedures. They also show that tickling could be delivered in a single bout before restraint rather than at both time points (before and after) to make it less time consuming and, thus, more practical."
"Tickling performed in association with a procedure, such as an injection, induces a positive affective state that mitigates the aversiveness of the procedure and makes the animals easier to handle. Tickling is more beneficial when applied pre- than post-procedure, thus providing a way to minimize potential welfare- and behavior-disruptive effects of routine medical procedures," Cloutier continued.
The study could have implications for laboratory animal welfare. "This study is important because it provides evidence that using a positive, playful handling technique is reducing rats’ fear of human and make procedures and handling less stressful. It is also important because the findings can be used to refine laboratory animal care standards and improve the quality and validity of data collected from animals used in biomedical research, as well as improving animal welfare," Cloutier added.
