Visualizing the reproductive tract of the female pig using real- time ultrasonography

The availability of inexpensive, lightweight, portable ultrasound machines will greatly facilitate the use of reproductive imaging in the female pig and may prove useful in making management decisions based on an accurate diagnosis of the reproductive status of the sow or gilt at any point in time. Real-time ultrasonography (RTU) using 3.5 and 5.0 MHz transducers transabdominally or 5.0 and 7.5 MHz transducers transrectally can allow the practitioner to determine the pregnancy and estrous status of breeding females in commercial herds. In our experience, less structural detail was visually revealed with transabdominal RTU when assessing the ovary or uterus during the estrous cycle or early pregnancy. In contrast, transrectal ultrasound allowed faster and more detailed means of assessing fine reproductive structures of varying echogenicity (follicles, corpora hemorrhagica [CH], and corpora lutea [CL]) and the conceptus components of early pregnancy (day 16–20). In this article, transrectal and transabdominal procedures are described in detail, and image specificity, quality, and ease of imaging of the female reproductive tract is considered. Reference sonograms are provided.