Water or Food Restriction or Deprivation
1. References: Guide for the Care and Use of Laboratory Animals: Eighth Edition. NIH, Diet Control in Laboratory Animals Guideline.
2.1. Standard Food Intake: Animals should be fed palatable, uncontaminated diets that meet their nutritional and behavioral needs at least daily, or according to their particular requirements (Guide, page 65).
2.2. Standard Water Intake: Animals should have access to potable, uncontaminated drinking water according to their particular requirements (Guide, page 67).
2.3. Food or Water Restriction: Any deviation from the standard food or water intake.
2.4. Food Deprivation: Withholding food for longer than 24 hours.
2.5. Water Deprivation: Withholding water for longer than 12 hours.
3. Purpose/Scope: The purpose of this policy is to establish standards and expectations for researchers performing food or fluid restriction in healthy animals for experimental purposes, and to communicate the importance of using the least amount of restriction necessary to achieve the scientific objective while maintaining the animals’ well-being.
3.1. This does not pertain to acceptable pre-anesthetic fasting procedures.
3.2. Restriction for research purposes needs to be scientifically justified and a program established to monitor physiologic or behavior parameters, including criteria for removal of an animal from the experiment (such as weight loss or hydration state).
3.3. When experimental situations require food or fluid restriction, at least minimum quantities of food and fluid should be made available.
3.4. Body weight loss must be limited, and at no point should the animal’s body weight fall below 80% of an age and sex matched ad lib fed control, unless scientifically justified in the IACUC protocol.
3.4.1. If young growing animals (rats or mice less than 14 weeks of age) are to be restricted, the investigator must ensure adequate nutrient intake to avoid malnutrition. The use of non-feed restricted littermates for comparison is optimal, but otherwise vendor growth chart comparisons for the appropriate strain can be used.
3.5. Precautions that should be used in cases of fluid restriction, to avoid dehydration, include daily recording of fluid intake and recording of body weight at least three times per week, or more often for smaller animals, such as rodents.
3.6. Special attention should be given to ensuring that animals consume a balanced diet, as food consumption may decrease with fluid restriction.
3.7. In the case of conditioned-response experiments, use of a highly preferred food (e.g. sweetened cereal) or fluid (e.g. sugar water) as a positive reinforcement, instead of restriction or to maintain behaviors once the animal is trained, is an acceptable alternative to food restriction.
4. Each water or food restriction or deprivation protocol must be scientifically justified by the investigator, and will be considered and reviewed by the IACUC on a case-by-case basis for approval.
5. An AV consult, prior to the IACUC meeting, is required for any water or food restriction or deprivation, per IACUC guideline #22.
6. Supersedes: IACUC Guideline #8: Water or Food Restriction 07/21/2011.
LAST REVIEWED AND ADOPTED BY THE IACUC: September 19, 2019