Benefits of ultrasound scanning during gestation in the small ruminant

Integration of ultrasonography into the breeding and gestational management of small ruminants is advantageous for producers, clinicians, and researchers. In the past decade, advances to ultrasound technology have improved the image quality and created probes that can image deeper into the uterus. Increased portability makes ultrasound possible and convenient on the farm. Pregnancy diagnoses can be made using transrectal or transabdominal ultrasound, and is most sensitive after day 30 of gestation in both the ewe and doe. The strongest indicator of pregnancy is the visualization of a fetus with a heartbeat, although fluid in the uterus and development of placentome structures are also indicative of pregnancy. Fetal number can also be determined during early- to mid-gestation, allowing prediction of litter size. As gestation advances, fetal features can be used to estimate gestational age and track growth over time. In addition, fetal sex may be determined during early gestation by the position of the genital tubercle or during mid-gestation by the presence of external genitalia. Thus, ultrasound is useful for producers, aiding with efficient culling and rebreeding decisions, fetal counting and sexing, and feeding the dam appropriately throughout the majority of gestation. Furthermore, ultrasound allows producers and clinicians to calculate parturition dates, monitor ewes and does susceptible to pregnancy toxemia during late gestation, supervise parturition, and monitor the fetus for abnormal growth in a non-invasive manner. These factors all contribute to proper gestational management in small ruminants that can ultimately improve animal health and growth, and operation efficiency and profitability. Thus, the objectives of this review are to evaluate the use of ultrasound in pregnant ewes and does while highlighting the benefits of ultrasound for production. This review also describes basic guidelines for ultrasound use by producers, clinicians, and researchers to encourage widespread adoption of ultrasound for small ruminant management.