Environmental enrichment for rhesus macaques: a cost-effective exercise cage.

Providing suitable and varied environmental enrichment opportunities for nonhuman primates is both challenging and expensive, requiring institutions to be innovative when planning an enrichment program. Equipment must be durable, nontoxic, easily sanitized and disinfected, and readily assembled or prepared by animal care personnel. We developed a portable exercise cage for singly housed macaques from pre-existing but outdated caging; our cage met the described requirements and was used in animal-holding rooms. Modifying existing caging for this purpose led to substantial cost savings. These cages have proved to be popular with animals and their affiliated research teams.