Related Experiment Video
Updated: Oct 16, 2025

Chronic Implantation of Whole-cortical Electrocorticographic Array in the Common Marmoset
Published on: February 1, 2019
Surgical removal of a telemetry system in a cynomolgus monkey (Macaca fascicularis): a 12-month observation study
Doo-Wan Cho1, Hyoung-Yun Han2, Mi-Jin Yang1
1Jeonbuk Branch Institute, Korea Institute of Toxicology, Jeongeup, Republic of Korea.
Background:
Telemetry is a wireless implanted device that measures biological signals in conscious animals and usually requires surgery for its removal when the study is finished. After removing the device, the animals are either used for other studies or euthanatized.
Case Presentation:
Herein, we report the case of a living cynomolgus monkey (Macaca fascicularis) that was used for the entire experimental period, instead of euthanasia, after surgical removal of an implanted telemetry system. Radiography was used to determine the status of the implanted telemetry, following which, a repair surgery was performed for removing the system; clinical signs were used to preserve the life of the cynomolgus monkey. Postoperative clinical signs, food consumption, hematology, and serum biochemistry were examined during the 12-month observational period. No abnormal readings or conditions were observed in the subject after implant removal.
Conclusions:
This study may be a useful case report for living cynomolgus monkeys in telemetry implantations used throughout the study period. We suggest minimizing the suffering and improving the welfare of these animals.

