Gestational Echobiometry In Brachycephalic Bitches Using High-Definition Ultrasonography1

M.C., Sim & otilde;es A.P.S., Uscategui R.A.R., Pavan L., Rodrigues M.G.K., Mariano R.S.G., Santos V.J.C. & Feliciano M.A.R. 2021. Gestational echobiometry in brachycephalic bitches using high-definition ultrasonography. Pesquisa Veterin & aacute;ria Brasileira 41:e06650, 2021. Departmento de Cl & iacute;nica e Cirurgia Veterin & aacute;ria, Faculdade de Ci & ecirc;ncias Agr & aacute;rias e Veterin & aacute;rias, Universidade Estadual Paulista "J & uacute;lio de Mesquita Filho", Via de acesso Prof. Paulo Donato Castellane s/n, Jaboticabal, S & atilde;o Paulo, SP 14884-900, Brazil. E-mail: marcusfeliciano@yahoo.com.brThe objective of the present study was to obtain echobiometric values for the most important canine maternal-fetal tissues using high-definition ultrasonography (HDUS) trying to update the formulas for predicting gestational age. Twelve healthy bitches of brachycephalic breeds weighing 7-13kg and aged one to four years were included. The fetuses were analyzed every day using conventional and high-definition ultrasonography from the eighth day after artificial insemination until the day of delivery, using the ACUSON S2000/SIEMENS ultrasound equipment and specific software. Embryonic and fetal structures; diameter of the embryonic vesicle; length of the embryo; biparietal diameter, abdominal length and kidney height; length of the femur, humerus, scapula, radius, and tibia; thickening of the stomach wall; adrenal length; and cardiac size were measured. These variables were correlated with gestational and adjusted tested according to regression models. The results obtained (P<0.001) for: lateral diameter of the gestational sac (R2=81.8%); length of the embryo (R2=85.7%); biparietal (R2=99.1%) and abdominal diameter (R2=97.2%); thickness of the gastric wall (R2=86.9%); length of the femur (R2=96.6%), radius (R2=97.5%), humerus (R2=96.5%), scapula (R2=95.8%) and tibia (R2=97.3%); kidney length (R2=95.8%) and height (R2=96.0%); adrenal length (R2=89.6%); heart length (R2=93.0%) and height (R2=91.5%) of the canine fetuses showed significant correlation with gestational days. This allowed monitoring fetal growth and estimation of age with high accuracy in different gestational periods.