Carbetocin - a long-acting oxytocin analogue - increases the blood supply to the reproductive tract of rams.

The aim of this study was to determine whether carbetocin administration alters blood flow in the reproductive tract and scrotal skin surface temperature of rams. Eight rams were evaluated in a crossover arrangement, in which each animal received a standard (0.2 mg/100 kg; STAC) or high (0.4 mg/100 kg; HIGHC) dose of carbetocin, or no treatment (CON). Each animal received all treatments. Hemodynamic characteristics of the male reproductive tract were assessed using spectral Doppler ultrasonography, and scrotal surface temperatures were recorded by infrared thermography at 0, 30, and 120 min after cabertocin administration. Thirty minutes after treatment, the resistive index (RI) of the internal iliac artery was lower in STAC than in CON (P=0.008) and HIGHC (P=0.02) treated rams. Carbetocin or its interaction with time did not affect blood flow in the marginal or supratesticular arteries or the scrotal surface temperatures. In conclusion, the standard dose of carbetocin transiently reduced internal iliac artery RI, resulting in a temporary increase in blood flow to the accessory sex glands, without altering scrotal skin temperature in rams.