The Center for Alternatives to Animal Testing is an academic center affiliated with the Division of Toxicological Sciences in the Department of Environmental Health Sciences of the Johns Hopkins University Bloomberg School of Public Health.

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Research Grants 2004-2005

Reducing Postoperative Pain and Distress in Mice

Alicia Z. Karas, DVM
Tufts University, Boston, Massachusetts

Scientists are asked to describe how they will care for mice after procedures such as surgery, in order to minimize pain and distress. A major obstacle is that relatively little is known about drugs and techniques that are effective in mice. There is a critical need to discover and publish information regarding the extent of postsurgical pain in the mouse, and techniques that reduce pain or distress.

We study the effects of pain-relieving drugs, nutritional support, anesthetic techniques and environment on mice recovering from surgery. Our model uses bodyweight monitoring and behavioral observation using a video camera system that films in both day and night lighting conditions. We demonstrated that following surgery, mice lose a significant percentage of body weight and also show marked reductions in activities such as climbing on the cage top, rearing, eating and exploring. When a single dose of a pain-reliever is given prior to surgery, weight loss is minimized and behavior patterns become more normal. We believe that this indicates dug weight loss and reduced activity may be in part due to pain. We are now examining whether giving more than one pain relieving drug or dose, adding intensive fluid and nutritional support; or altering the environment can further improve well-being. We are also looking to see whether the type of anesthesia used contributes to improved outcome. The goal is to improve the well-being of mice used in science, increase the overall awareness of rodent procedural pain in science, and make the task of ensuring minimization of pain and distress a realistic objective for scientists.