Transrectal ultrasonographic evaluation of combined utero-placental thickness during the last half of pregnancy in Martina Franca donkeys

In the recent years the donkey population decreased dramatically so that many breeds are presently considered as endangered. In comparison to the horse, the donkey placenta still remains not completely studied. In the horse, one of the diagnostic tool useful to identify pregnant mares at risk of abortion or premature delivery, include the transrectal ultrasound examination of the uterus and its contents, and especially of the combined thickness of the uterus and of the placenta (CUPT). Since the CUPT was never investigated in donkeys, the present study was aimed to define the transrectal CUPT values during the last half of pregnancy in 20 Martina Franca jennies. Foalings times, foals characteristics and placental gross appearance and measurements were also evaluated and values resulted always within normality. Differently to the mare, a continuous significant CUPT increase between the 6th to the 12 month of pregnancy, and a substantial increase from the 9th to the 12th month of pregnancy, was found. Although statistically not evaluable, the CUPT values recorded from 3 jennies with pregnancy loss did not show evidence of CUPT increases. In conclusion, normal CUPT values from the 6th to the 12th month of pregnancy in Martina Franca donkeys are provided, but further investigations are needed to define possible breed or body-size CUPT specific differences, as well as the CUPT values during pregnancy disturbances or placental abnormalities