Comparison of and Habituation to Four Common Methods of Handling and Lifting of Rats with Cardiovascular Telemetry
Daily routines in the animal house may influence the results and interpretation of experiments. Handling is one such routine since it is necessary to immobilize animals for even minor procedures. This study assesses the influence of four common handling and lifting methods on cardiovascular parameters (blood pressure, heart rate) and locomotor activity of Sprague-Dawley and Wistar rats. Seven rats were implanted with radio-telemetry transmitters. After a recovery period, they were housed in groups of three with two intact rats. Each instrumented rat was subjected to the four methods of handling and lifting (scruff, encircling, plastic cone, lifting and holding by the tail on the arm) and, the same method was repeated during three consecutive weekdays. The method was changed every second week in a rotational order. Handling increased cardiovascular parameters for about 30 min, these changes being statistically significant (p < 0.05) as compared to control conditions immediately before the procedure. With holding by the scruff, the response duration decreased significantly from day one to days two and three, indicative of habituation to this procedure. Rats did not habituate to the cone handling, nor to encircling or lifting and holding by the tail; with the restraint cone being apparently the most disturbing. In conclusion, we have found that there are measurable differences in the impact of various handling and lifting methods and the correct choice permits refinement (one of the “Three Rs” of animal usage) of the procedure. Cardiovascular telemetry appears to be a useful method when used for refining procedures on animals, such as handling and lifting.