Reference range of the gestational uterine artery resistance index in toy canine breeds

BATISTA PR; GOBELLO C; RUBE A; VERCELLINI R; TORTORA, M; RODRÍGUEZ R; ARIAS DO; BLANCO PG

Simposio; 8th International Symposium on Canine and Feline Reproduction 2016; 2016

EVSSAR

The objectives of this study were to describe and to determine reference values of resistance index (RI) of the uterine artery during normal pregnancy in toy dogs. For these purposes, fifty-two, 1?6 years old, 1.5?6.5 kg, purebred healthy pregnant bitches were included in this study. The dogs were evaluated by Doppler ultrasound every 10 days from day 30 of the estrous cycle to parturition. Uterine body was observed with two-dimensional ultrasound in a transversal axis. Color Doppler was used to localize uterine arteries at both sides of the uterine body and pulsed-wave Doppler was performed to obtain the waveforms[1]. Peak systolic velocity (PSV; m/s) and end diastolic velocity (EDV; m/s) were measured while RI [(PSV−EDV)/PSV] was automatically calculated[2]. Peak systolic velocity, EDV and RI of the left and right uterine arteries were compared using Student?s t-tests. Values of PSV, EDV and RI were analyzed by repeated measures ANOVA followed by Tukey test. Also, a covariance analysis was carried out to assess the influence of age, litter size and parity on RI. RI reference ranges were constructed by regressing this index on gestational age (GA). Polynomial regression model was fitted to mean. The information about standard deviation of the measurement is contained in the residuals around the fitted curve. Equation of the polynomial regression curves were used to calculate the mean, 2.5th and 97.5th centiles for each gestational age (SPSS 19.0, SPSS Inc. Chicago, IL, USA)[3]. All the females whelped normally 2 to 6 healthy puppies. No differences were found between right and left uterine arteries (P>0.1), therefore values of PSV, EDV and RI were averaged. A gradual increase of PSV (P