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

44 GUIdE FOR ThE CARE ANd USE OF LAbORATORy ANIMALS1993; Pennycuik 1967). These effects can be multigenerational (Barnett1965, 1973).The dry-bulb temperatures listed in Table 3.1 are broad and generallyreflect tolerable limits for common adult laboratory animal species, providedthey are housed with adequate resources for behavioral thermoregulation;temperatures should normally be selected and maintained with minimalfluctuation near the middle of these ranges. Depending on the specifichousing system employed, the selection of appropriate macro- and microenvironmentaltemperatures will differ based on a variety of factors, includingbut not limited to the species or strain, age, numbers of animals in theenclosure, size and construction of the primary enclosure, and husbandryconditions (e.g., use/provision of contact bedding, nesting material and/orshelter, individually ventilated cages). Poikilotherms and young birds ofsome species generally require a thermal gradient in their primary enclosureto meet basic physiological processes. The temperature ranges shown maynot apply to captive wild animals, wild animals maintained in their naturalenvironment, or animals in outdoor enclosures that have the opportunity toadapt by being exposed to seasonal changes in ambient conditions.Some conditions require increased environmental temperatures forhousing (e.g., postoperative recovery, neonatal animals, rodents with hairlessphenotypes, reptiles and amphibians at certain stages of reproduction).The magnitude of the temperature increase depends on housing details;sometimes raising the temperature in the microenvironment alone (e.g.,by using heating pads for postoperative recovery or radiant heat sourcesfor reptiles) rather than raising the temperature of the macroenvironment issufficient and preferable.Relative humidity should also be controlled, but not nearly as narrowlyas temperature for many mammals; the acceptable range of relative humidityis considered to be 30% to 70% for most mammalian species. Micro-TABLE 3.1 Recommended Dry-Bulb Macroenvironmental Temperaturesfor Common Laboratory AnimalsDry-Bulb TemperatureAnimal °C °FMouse, rat, hamster, gerbil, guinea pig a 20-26 68-79Rabbit 16-22 61-72Cat, dog, nonhuman primate 18-29 64-84Farm animals, poultry 16-27 61-81a Dry-bulb room temperature settings for rodents are typically set below the animals’ LCT toavoid heat stress, and should reflect different species-specific LCT values. Animals should beprovided with adequate resources for thermoregulation (nesting material, shelter) to avoidcold stress.