Guide for the Care and Use of Laboratory Animals - Office of ...

ANIMAL CARE ANd USE PROGRAM 31least restriction necessary to achieve the scientific objective while maintaininganimal well-being.The development of animal protocols that involve the use of food orfluid regulation requires the evaluation of three factors: the necessary levelof regulation, potential adverse consequences of regulation, and methodsfor assessing the health and well-being of the animals (NRC 2003b). In addition,the following factors influence the amount of food or fluid restrictionthat can be safely used in a specific protocol: the species, strain, or stock,gender, and age of the animals; thermoregulatory demand; type of housing;time of feeding, nutritive value, and fiber content of the diet (Heiderstadt etal. 2000; Rowland 2007); and prior experimental manipulation. The degreeof food or fluid restriction necessary for consistent behavioral performanceis influenced by the difficulty of the task, the individual animal, the motivationrequired of the animal, and the effectiveness of animal training for aspecific protocol-related task.The animals should be closely monitored to ensure that food andfluid intake meets their nutritional needs (Toth and Gardiner 2000). Bodyweights should be recorded at least weekly and more often for animalsrequiring greater restrictions (NRC 2003b). Written records should be maintainedfor each animal to document daily food and fluid consumption,hydration status, and any behavioral and clinical changes used as criteriafor temporary or permanent removal of an animal from a protocol (Morton2000; NRC 2003b). In the case of conditioned-response research protocols,use of a highly preferred food or fluid as positive reinforcement, instead ofrestriction, is recommended. Caloric restriction, as a husbandry techniqueand means of weight control, is discussed in Chapter 3.Use of Non-Pharmaceutical-Grade Chemicals and Other Substances Theuse of pharmaceutical-grade chemicals and other substances ensures thattoxic or unwanted side effects are not introduced into studies conductedwith experimental animals. They should therefore be used, when available,for all animal-related procedures (USDA 1997b). The use of non-pharmaceutical-gradechemicals or substances should be described and justified inthe animal use protocol and be approved by the IACUC (Wolff et al. 2003);for example, the use of a non-pharmaceutical-grade chemical or substancemay be necessary to meet the scientific goals of a project or when a veterinaryor human pharmaceutical-grade product is unavailable. In suchinstances, consideration should be given to the grade, purity, sterility, pH,pyrogenicity, osmolality, stability, site and route of administration, formulation,compatibility, and pharmacokinetics of the chemical or substance tobe administered, as well as animal welfare and scientific issues relating toits use (NIH 2008).