in this section of the DVD I'm going to be talking about scanning ovaries and the non pregnant uterus and we'll cover the following topics mare reproductive anatomy how ultrasound works basic scanning procedure the equine estrus cycle follicles ovulation and uterine edema CHS and CLS uterine fluid and endometrial cysts the entire reproductive tract sits on top of the digestive system which for purposes of this diagram has been removed but when present elevate the entire reproductive tract up near the spine so that the horns are located near the rectum the ovaries are actually located near the kidney or at the point of the hip near the hollow of the loin when inserting an arm into the rectum one of the first structures that is seen on ultrasound is the bladder which is located directly below the vagina the uterine body is located at the front or in front of the bladder next we will see the uterine horns followed by the ovary the oviduct which is shown here in this diagram is enlarged and is actually too small to be seen by ultrasound will now move from this diagram here over to this diagram here which is an aerial view of the mayor's reproductive tract the rectum lies over the top of the mayor's reproductive tract and for purposes of bringing clarity to this diagram and has been removed when inserting an arm into the rectum the first structure that you see is the vagina followed by the uterine body and then the uterine horns the points at which the uterine horns come off the uterine body are called the bifurcations this being the left bifurcation and this being the right bifurcation the uterine horns in this diagram are shown in a tee position but oftentimes the uterine horns are rotated upward in a Y position which will become important when we talk about scanning for ovaries recall that the reproductive tract is suspended by the broad ligament and sits loosely on top of the digestive system also the oviduct which is seen here in this day Graham is not seen by ultrasound and the ovary is located a short distance from the tip of the uterine horn these two anatomical features often make it challenging to find the ovaries in this section of the DVD we will be presenting actual scans of ovaries we're first going to learn to follow the uterus because the uterus is your guide to the ovaries given that the ovary can be found in a variety of locations since it hangs loosely from the broad ligament it's important to be able to follow the uterus to get you in the right ballpark in order to find the ovaries upon entering the rectum with the probe pointed downward in the six o'clock position or perhaps at five or seven o'clock the first main structure that you will run into will be the bladder normally fluid appears black on the ultrasound screen however mare urine contains other constituents and can appear anywhere from dark gray to light gray in color in this image the bladder is light gray in color and also very large which is normal red arrows have been placed on the image to indicate the borders of the bladder once you have found the bladder rotating the probe to the left or to the right and moving it slightly forward is a good technique to use to help find the uterine body in this image red arrows have been used to identify the borders of the uterine body the left side of the screen is the front or anterior portion of the uterine body from this position we will rotate to the left or to the right to pick up one of the uterine horns which will be followed as a guide to the ovary the red arrows indicate the boundaries of the uterine horn which is round in cross-section as we move up the uterine horn it gets smaller in diameter and eventually disappears from view as shown here once the uterine horn disappears you continue to rotate upward until you run into the ovary as you're rotating upward it is often necessary to go several inches further into the mare as the ovary is frequently located deeper than the tip of the uterine horn in this image you can see the ovary beginning to appear with several follicles red arrows are used to indicate the boundaries of the ovary notice that the ovary is more than just follicles the gray area between the follicles is ovarian tissue once the ovary has been found you rotate up on the ovary until the follicles disappear and then rotate back down on the ovary again until the follicles disappear this ensures that you have seen the entire ovary and can identify the largest follicle once you have located the largest follicle and measured it rotate back down from the ovary onto the uterine horn follow the uterine horn back to the uterine body and then rotate towards the other uterine horn follow that uterine horn up until it disappears once it disappears continue to rotate upward until you run into the other ovary again scan all the way up until the ovary disappears once it disappears rotate back downward until it disappears again ensuring that you found the largest follicle