The effect of melatonin implant on estrous cycle and hepatic and renal function in the bitch

The increasing of melatonin has stimulating and inhibiting effects on reproductive patterns in different animal species. Controlling the estrous cycle using hormonal methods with minimal side effects and easy administration is very important in dog reproduction. This study aimed to evaluate the effect of melatonin implant (18 mg) on some reproductive factors and function of kidney and liver in female dogs. In this study, ten adult non-pregnant female mixed breed dogs enrolled in two equal control and melatonin groups. Melatonin implant (18 mg) was administrated in subcutaneous space of neck. Blood samples, ovarian ultrasonography, and vaginal cytology were performed weekly for nine weeks. The mean diameter of ovaries and serum concentration of estrogen, progesterone, ALP, ALT, creatinine, and BUN were not significantly different between the two groups. Vaginal cytology and changes of hormones showed regularly the estrous cycles. In conclusion, the administration of subcutaneous melatonin implant could not significantly affect the reproductive factors in female dogs likewise did not affect hepatic and renal functional parameters.