Abstract
Lasia spinosa Thwaites (LST) has emerged as a potential supplement for enhancing male reproductive performance. This study evaluated the effects of long-term oral supplementation with LST on hematological parameters, semen characteristics, ultrasonographic measurements of the prostate gland and testes, and the cryopreservation potential of canine sperm. Six healthy male dogs received oral LST supplementation at a dosage of 10 mg/kg body weight once daily for 7 days (short-term). After a three-month washout period to ensure full physiological recovery, the same dogs underwent a long-term supplementation protocol (60 days). In the short-term trial, no clinically significant changes were observed in hematological or serum biochemical parameters, including complete blood count, alanine aminotransferase, creatinine, blood urea nitrogen, total protein, and albumin; all parameters were within normal reference ranges. Serum testosterone levels and semen characteristics were also unaffected (p > 0.05). During the long-term treatment, blood profiles and testosterone levels remained stable. Although prostatic and testicular volumes increased slightly, the changes were not statistically significant (p > 0.05). A significant increase in semen volume was observed (p < 0.05), while other semen parameters showed no significant differences. Notably, post-thaw sperm motility significantly improved at both 15 min and 4 h after thawing, and sperm viability was significantly enhanced at 4 h post-thaw (p < 0.05), suggesting a potential protective effect of LST during cryopreservation. These findings indicate that LST supplementation is physiologically safe and may improve canine sperm quality during freezing and thawing, supporting its potential application in reproductive health management.