Ultrasonographic diagnosis of twins in two pregnant bitches: case report

ABSTRACT Multiple pregnancies in humans account for only 3% of pregnancies, 97-98% of which are twin pregnancies and the morbimortality is higher in the monochorionic twins when compared to dichorionic ones. The canine species is naturally multiparous, but the diagnosis of monochorionic twin pregnancy is not common. The objective of this report was to describe the ultrasonographic diagnosis of monochorionic twin pregnancies in two bitches [Pug (case 1) and Shih tzu (case 2)]. It was possible to verify the presence of one gestational vesicle containing two fetuses in each female by observing two heads or two bodies within the same placental site. These fetuses presented adequate viability and normal organogenesis. Their development was similar to the other fetuses. In case 1 they were stillborn and smaller than the other five live-born fetuses. The twins in case 2 were born alive, but they also appeared smaller when compared to the littermates. The gestational risks associated with this condition in pregnant bitches are still unknown, however, there are reports of fetal death in monochorionic pregnancies in this species. Therefore, ultrasonographic exam during pregnancy allows an early monochorionic diagnosis and monitoring the fetal viability could bring health benefits to both the female and the littermates.