For the purposes of these regulations, comfortable and satisfactory housing is defined as any system of management, care, and housing that permits animals to be maintained in good health. Some of the specific considerations that give meaning to this definition are outlined below:
A. Criteria for Evaluating a Caging or Housing System.
(1) It should be designed with the animals' physical comfort as a primary consideration. Physical comfort, as applied scientifically to the housing system, includes keeping the animal dry and clean, maintaining the animal in a state of relative thermal neutrality, providing sufficient space to assure freedom of movement, and allowing for normal postural adjustments, avoiding unnecessary physical restraint, providing convenient access to appropriate food and water, and, if animals are group housed, maintaining them in compatible groups without overcrowding.
(2) It should be compatible with the maintenance of the animals in good health as measured by such factors as the maintenance of normal body weight and the prevention of the spread of communicable diseases.
(3) It should be designed to facilitate effective sanitary maintenance and technical servicing.
(4) Cages, runs, and pens should be kept in good repair to prevent injury to the animal and to promote physical comfort. Sharp corners and edges, broken wires, and any dangerous surfaces shall be immediately covered.
(5) Materials used for the caging of animals shall be impervious to water, to wear, and to corrosion. Wood is an unacceptable caging material.
B. Exercise. An area readily susceptible to proper sanitation shall be available for the sole purpose of exercising animals.