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

42 GUIdE FOR ThE CARE ANd USE OF LAbORATORy ANIMALSreptiles and certain amphibian species, are terrestrial. Personnel workingwith aquatic animals should be familiar with management implications,e.g., the importance of providing appropriate temperature ranges for basicphysiologic function.TERRESTRIAL ANIMALSTerrestrial EnvironmentMicroenironment and MacroenironmentThe microenironment of a terrestrial animal is the physical environmentimmediately surrounding it; that is, the primary enclosure such asthe cage, pen, or stall. It contains allthe resources with which the animalscome directly in contact and alsoMicroenvironment: The immediatephysical environment surroundingthe animal (i.e., the immediate environment. The micro-provides the limits of the animals’environment in the primary enclosuresuch as the cage, pen, factors, including illumination, noise,environment is characterized by manyor stall).vibration, temperature, humidity, andgaseous and particulate compositionof the air. The physical environmentof the secondary enclosure, such as a room, a barn, or an outdoor habitat,Macroenvironment: The physicalenvironment of the secondaryenclosure (e.g., a room, abarn, or an outdoor habitat).constitutes the macroenironment.Although the microenvironment and the macroenvironment are generallyrelated, the microenvironment can be appreciably different and affectedby several factors, including the design of the primary enclosure and macroenvironmentalconditions.Evaluation of the microenvironmentof small enclosures can be difficult.Available data indicate thattemperature, humidity, and concentrationsof gases and particulate matterare often higher in the animalmicroenvironment than in the macroenvironment(Besch 1980; Hasenauet al. 1993; Perkins and Lipman 1995; E. Smith et al. 2004), while lightlevels are usually lower. Microenvironmental conditions can directly affectphysiologic processes and behavior and may alter disease susceptibility(Baer et al. 1997; Broderson et al. 1976; Memarzadeh et al. 2004; Schoebet al. 1982; Vesell et al. 1976).