Triplex Doppler evaluation of uterine arteries in cyclic and pregnant domestic cats

The aims were to determine resistance index (RI) and pulsatility index (PI) in the uterine arteries of cyclic and pregnant domestic cats comparing the left and right uterine horns, as well as the majority or minority uterine horns, based on fetus number per horn; to determine the presence or absence of an early diastolic notch (EDN) in the uterine artery of pregnant queens. Ten domestic cats were followed during one cycle and one pregnancy until 63rd days after mating. The estrous cycle length was 16 ± 9.57 days. The uterine horn with the highest number of fetuses (majority uterine horn – MUH) presented 2.0 ± 1.0 fetus and the lower (minority uterine horn – miUH) presentes 0.78 ± 0.67 fetus. There were no differences in indexes between uterine arteries during the cycles and pregnancies. The RI and PI of MUH were lower than miUH (P < 0.05). Uterine artery of the MUH presented lower indexes than miUH during the acceptance period (P < 0.05). On D14 of pregnancy, uterine artery presented reductions in both indexes for the miUH. On D56, the PI was reduced in the miUH. The indexes depended on the week of pregnancy. EDN was present on the uterine arteries of all cats until D35, but disappeared by D49. The blood flow varied according to the category of horn.