Sonographic Changes During Gestation In Primiparous Chinchilla Rabbit Does

Abstract

Sonographic changes during gestation were evaluated in ten primiparous female Chinchilla rabbits with mean weight 1.9±0.1kg. The rabbits were synchronized with 2mg/kg intramuscular injections of prostaglandinF2α, mated naturally and thereafter examined sonographically on day 7, 14, 21 and 27 after mating using an ultrasound machine. Measurements of diameters of gestational sac, embryonal sac and fetal sac were obtained. Heart beats of at least two fetuses were also counted manually and the average determined. Descriptive statistics were used to analyze the sonographic measurements. The results showed that the earliest sonographic feature of pregnancy observed in the rabbit was the gestational sac observed by day 7 after mating and was characterized by oval shaped anechoic sac containing bipolar hyperechoic band. The mean diameters of the gestational sacs in the rabbits were 7.3±0.71mm. The embryonal sac was observed by day 14 after mating, which was characterized by an oval shaped hyperechoic band with central anechoic cavity and some hyperechoic structures. The mean diameter of the embryonal sacs was 16.1±1.79mm. Fetal sac, fetal skeletal structures, fetal movement and fetal heartbeat were first detected on day 21 and 27 after mating. The mean diameter of the fetal sac on day 21 and 27 were 21.8±1.39mm and 36.4±3.20mm respectively, the mean fetal heart rate on day 27 after mating was 125.3±14.3beats per minute. It was thus concluded that sonographic changes during pregnancy in rabbits is valuable in predicting gestational length and fetal viability. The values obtained in this study can serve as baseline reference for comparison with other breeds.