Animals are routinely subjected to painful procedures, such as tail docking for puppies, castration for piglets, dehorning for dairy calves, and surgery for laboratory rats. Disease and injury, such as tumours in mice and sole ulcers on the feet of dairy cows, may also cause pain. In this paper we describe some of the ways in which the pain that animals experience can be recognized and quantified. We also describe ways in which pain can be avoided or reduced, by reconsidering how procedures are performed and whether they are actually required. Ultimately, reducing the pain that animals experience will require scientific innovation paired with changed cultural values, and willingness to address regulatory, technological and economic constraints.
Weary, D. M., Niel, L., Flower, F. C., & Fraser, D. (2006). Identifying and preventing pain in animals. Applied animal behaviour science, 100(1), 64-76.