Original Research ArticleUterine blood flow in sheep and goats during the peri-parturient period assessed by transrectal Doppler sonography

- This is the first study concerning the uterine blood flow changes during early puerperium in sheep or goats.
- Colour Doppler ultrasound is a successful tool to follow changes in uterine arterial blood flow (UBF) during early puerperium.
- Doppler indices such as blood flow acceleration and time averages mean velocity could be used successfully for assessing changes UBF during the postpartum period in small ruminants.
- Doppler blood flow indices are correlated with the uterine and ovarian changes during early puerperium in small ruminants.

The aim of the present study was to evaluate uterine blood flow (UBF) during the postpartum period in small ruminants. The study involved measures of UBF in 5 ewes and 5 goats during the first 4 weeks after parturition. Transrectal quantification of UBF was assessed by determining the diameter (DM), time averaged mean velocity (TAMEAN), blood flow volume (BFV), blood flow acceleration (ACCE) and pulsatility index (PI) in the uterine arteries ipsilateral to the previously gravid uterine horn(s) at Wk 20 of gestation and every 3 days from the day of parturition (D 0) until Day 27 postpartum (D 27). The diameters of the uterine arteries decreased (P < 0.01) in both species during the postpartum period. The results revealed decreases (P < 0.0001) in BFV, ACCE and TAMEAN, while PI increased during the postpartum period in both sheep and goats. Furthermore, there were positive correlations (P < 0.05) between blood flow parameters in sheep and goats, respectively (BFV and DM, r = 0.62 and 0.58; BFV and ACCE, r = 0.32 and 0.26; BFV and TAMEAN, r = 0.51 and 0.37). There were negative correlations (P < 0.05) between PI and other parameters (PI and BFV, r = −0.39 and −0.36; PI and DM, r = −0.54 and −0.24; PI and ACCE, r = −0.58 and −0.48; and PI and TAMEAN, r = −0.80 and −0.79) in sheep and goats, respectively. Altogether, these results indicate that non-invasive Doppler ultrasound parameters provide important information toward understanding changes in the vasculature and its perfusion of the uterus during the postpartum period in sheep and goats.