One of the most common pitfalls when beginning with veterinary ultrasound is the confusion between bowel and pregnancy. Loops of bowel can look very like early gestational sacs to the untrained eye; they are circular, black shapes, sometimes with what looks like something small inside. As attendees of our canine ultrasound training course will know, the two can be quickly and easily distinguished by rotating your probe head. Bowel will elongate (become sausage-shaped); a gestational sac will always remain circular, no matter how you rotate over it.

You can also watch bowel for a few seconds, and you will probably see gas and food swirling through it as the intestines' smooth muscle squeezes it through. Gas inside the intestines also create bright slivers of light, as explained by sonographer Sarah on the SonoScape S6v below.