Early pregnancy diagnosis using ultrasonography in goats

Abstract

The objective of the study was to evaluate the efficacy of B-mode ultrasonography in early pregnancy diagnosis in goats and to identify the optimum stage of gestation for early pregnancy diagnosis using of transrectal and transabdominal ultrasonography. Thirty apparently healthy does with the history of breeding were selected for the study and these goats were randomly divided into three groups consisting of ten animals each. Group I consisted of ten goats which were scanned between third and fourth week (15- 28 days) post-breeding. Ten goats scanned between fifth and sixth week (29- 42 days) post-breeding, were included in group II and group III consisted of ten goats which were scanned between seventh and eighth week (43- 56 days) post-breeding. These animals were subjected to B-mode real-time ultrasound scanning transrectally (7.5 MHz probe)) and transabdominally (3.5 MHz probe). The accuracy of transrectal scanning in group I, II and III was 90, 100 and 100 per cent respectively and the accuracy for corresponding weeks was 50, 100 and 100 per cent respectively for transabdominal scanning. The embryonic vesicle was detected earliest on day 19 of gestation by transrectal scanning and on day 26 by transabdominal scanning. The embryo was first observed on day 22 and day 28 by transrectal and transabdominal scanning respectively. The foetal heartbeat which was an indication of foetal viability was detected earliest by transrectal scanning on day 24 of gestation. But by transabdominal ultrasonography, it could be detected only on day 34 of gestation. Placentomes and foetal skeleton were observed on day 42 and 54 of gestation respectively using both methods of scanning. The mean diameter of gestational sac recorded was 5.1 mm on day 19 and 27 mm on day 36 of gestation by transrectal scanning. The mean diameter of gestational sac recorded was 15.7 mm on day 26 and 34.4 mm on day 36 of gestation by transabdominal scanning. The mean crown-rump length ranged from 7.2 mm on day 22 to 34.4 mm on day 43 of gestation using transrectal scanning. By transabdominal scanning, the mean crown-rump length recorded was 16.7 mm on day 28 and 32.7 mm on day 43 of gestation. The diameter of the placentomes recorded by transrectal and transabdominal scanning on day 42 of gestation was 8.4 mm and 8.5 mm respectively. All the foetal measures by transrectal and transabdominal scanning were highly correlated (r > 0.9) with gestational age. The overall accuracy for the prediction of foetal numbers by transrectal and transabdominal scanning was 80 and 50 per cent respectively. The accuracy for prediction of foetal number using transrectal scanning in pregnant animals of group I and III was 71.43 per cent. The accuracy for the prediction was 100 per cent in pregnant animals of group II. By transrectal scanning, the accuracy for the prediction of singletons, twins and triplets by transrectal scanning was 100, 83.33 and 50 per cent respectively. By transabdominal ultrasonography, it was not possible to predict foetal number accurately in pregnant animals group I. The accuracy for the prediction of foetal number in group II by transabdominal scanning was 66.66 per cent while it was 85.71 per cent in group III. . The accuracy for the prediction of singletons, twins and triplets by ultrasonography was 50, 58.33 and 25 per cent respectively. In conclusion, transrectal scanning was accurate for pregnancy diagnosis from fourth week of gestation and transabdominal from fifth week of gestation and that real-time ultrasound scanning by both transrectal and transabdominal approaches was found to be reliable, safe and accurate for the diagnosis of pregnancy in goats from fifth week of gestation.