Some research protocols require surgical procedures. Experimental surgery is often referred to as major or minor, depending on the nature of the procedure. Both major and minor surgical procedures are potentially painful and can have negative effects on the well-being of the subject animal. Surgical procedures should be carefully considered to determine the least-invasive and least-stressful method of accomplishing the research goal. Most minor procedures and all major procedures are carried out under general anesthesia. Therefore, the well-being of a subject animal is most likely to be compromised during the postoperative or healing period. Although humans can indicate when they do or do not wish to use analgesics to contend with temporary postsurgical pain, nonhuman primates cannot so indicate and so should be given analgesics to prevent distress and reduce pain. Appropriate use of analgesics should result in improved appetite and more interaction of an animal with its environment (NRC 1992), but care should be taken that sutures are not removed by the animal.
It should also be recognized that surgery performed with the goal of altering the normal function of a physiological system can affect the psychological well-being of animals in the postsurgical period. Such procedures include those which reduce a subject's ability to interact socially or with the environment. Examples are procedures that result in impaired sensory perception, limit an animal's movement capacities, and impair cognitive abilities. After those procedures, appropriate accommodations should be made in an animal's housing environment or access to enrichment devices to maximize the extent to which it can interact socially and with the environment. Such accommodations can include housing the animal in a social group where it will not be subject to aggressive attacks, giving it manipulable objects that can be used with a particular sensory or motor deficit, and giving increased personnel attention to an animal that can no longer be put in social housing.
Nonhuman primates are long-lived, expensive, and often threatened with extinction in nature. Animals maintained in a state of good health and well-being can contribute to research for many years. Facilities should assume that many nonhuman primates will participate in multiple studies and plan accordingly. This committee believes that appropriate multiple use of primates is in the best interest of conservation goals. Appropriate rest and recovery periods should be provided after each protocol that an animal participates in.
A subject of some controversy is the use of primates for multiple survival surgical projects. With most species, multiple survival surgery is not recommended; however, multiple survival surgery using nonhuman primates should be considered. To conserve as many animals as possible and maximize the long-