Rosales, C., Sands, C. 2022. Confirming sexual maturity in male cynomolgus macaques by urinary spermatozoa microscopic examination. Laboratory Animal Science Professional 10(1) (January/February), 60-61.

Medications often require studies performed in sexually mature cynomolgus macaques. At this time, there are few options available to confirm sexual maturity in male macaques. Electroejaculation and collection of seminal fluid are invasive and require either anesthesia or prolonged acclimation. Testicular volume is, at best, a surrogate and does not reliably confirm that the animal is sexually mature and producing sperm. It was hypothesized that spermatozoa could be found in a urine sample post ejaculation, thereby verifying sexual maturity. Urine sample collection is performed at the beginning of the day before husbandry staff members wash the animals' cages. The veterinary technician collects the urine sample from an easy to obtain, flat surfaced cage pan using a 3mL syringe. In conclusion, we found that confirming sexual maturity in male Cynomolgus macaques via the presence of spermatozoa in urine, improved time efficiency and the overall sexual maturity confirmation rate.