Crab-eating macaque findings. One of the most well known examples of experiments on crab-eating macaques is the 1981 Silver Spring monkeys case. In 2014, 21,768 crab-eating macaques were imported in the United States to be used in experimentation. The crab-eating macaque has the third-largest range of any primate species, behind only humans and rhesus macaques. The IUCN Red List categorizes the species as Least Concern, and CITES lists them as Appendix II ("not necessarily threatened with extinction", in which trade must be controlled to avoid use incompatible with their survival). A recent review of their populations suggests a need for better monitoring
Organ replacement in animals to aid horses with bowed tendons, research has been done using carbon fiber implants that consist of about 40,000 fibers in total each of which is 8 micrometres in diameter. These fibers induce tissue growth and result in a structure of carbon and tissue about 8 mm in diameter. Organ replacement in animals Limb replacement (prosthesis) in animals is a well developed science and becoming more common. Organ replacement is rarer and much more difficult. The first pacemaker surgery on a dog was performed in 1968. About 300 pacemakers are implanted in dogs each year. Successful kidney transplants in cats