restriction/deprivation protocols involving animals are often
necessary for behavioral training. Because these protocols have
the potential for causing significant distress to the animal,
the Animal Research Committee (ARC) has established the
The least restriction that will achieve
the scientific objective should be used. In the case of
conditioned-response research protocols, use of a highly
preferred fluid as positive reinforcement, instead of
restriction, is recommended.
Due to individual species and strain
variations in water requirements, average guidelines for
water intake or urine output are not appropriate.
Every protocol involving water restriction in
non-human primates should be individually evaluated. In
general, any non-human primate given less than 80 ml/kg/day
is considered water restricted. Primates are not allowed
less than 22 ml/kg/day. Protocols involving water
restriction in primates must be discussed with a DLAM
veterinarian. The monitoring schedule and criteria for
suspension of water restriction established by the
veterinarian must be followed at all times.
Water restricted/deprived animals—regardless
of species—must be monitored daily for continued good health
as judged by stability in weight, stability of performance
in the experimental protocol, development of signs of
dehydration (skin turgor, mucous membrane dryness, urine
output and specific gravity, blood analysis), and
development of signs of stress. Weight must be monitored
daily and records on body weight must be kept. Animals must
not lose body weight in excess of the limit indicated in the
approved protocol. In general, the ARC limits weight loss
to 10% unless scientific justification is approved by the
ARC for exception to this policy. Disturbances in normal
behavior and activities can signal stress, including changes
in normal sleep cycles, abnormal social interactions, and
emergence of abnormal behaviors such as thumb sucking, cage
chewing, hair picking, abnormal vocalizations, and
aggression. Careful evaluation of the animal for
physiologic signs of dehydration should be performed should
signs of stress become evident.
Investigators utilizing water
restriction/deprivation protocols must communicate with the
animal care staff. To prevent animals from receiving
improper rations, the staff must be informed about periods
of restriction/deprivation and about rest periods when full
or supplemental water can be provided.
To communicate to the veterinary and animal
care staff during periods of water restriction/deprivation,
special treatment cards must be placed on the cage
indicating that the investigator’s laboratory will be
responsible for watering animals, and the duration (start
and end dates) for this special watering schedule must be
noted on the card. Special treatment cards may be obtained
from DLAM; please consult with them as to the proper card(s)
to use and the information they must contain.
The above policy does not apply to water
restriction prior to surgery or anesthesia. It is typically
not necessary to water-restrict an animal prior to surgery
or anesthesia, except for non-human primates. It is
essential that pigs NOT be water restricted at any time.
For consultation on water restriction or deprivation prior
to surgery or anesthesia, please consult with a DLAM
Guide for the Care and
Use of Laboratory Animals. National
Research Council, pp. 30-31, 2010.
Guidelines for the Care
and Use of Mammals in Neuroscience and Behavioral Research.
National Research Council, pp. 49-61, 2003.
Orlans, F.B. Prolonged
water deprivation: A case study in decision making by an IACUC.
Institute of Laboratory Animal Resources (ILAR) News,
Vol. 33, pp 48-52, 1991.
Desimone, R., C. Olson, and
R. Erickson. The controlled water access paradigm. ILAR
News, Vol. 34, pp 27-29, 1992.
Hughes, J.E., et al. Health
effects of water restriction to motivate lever pressing in
rats. Laboratory Animal Science, Vol. 44, pp
Revised 1/28/02, 7/26/04, 7/26/10; Updated 1/18/11