I'm no expert either, but it was no 2-5 gallons of fluid. It was... If I was to estimate... a third of a cup. Though it happened at least one more time while I was out there. I'm trying not to worry myself to death here, but I'm pretty sure the fluid came from her rectum, not her vulva. At first glance, it looked like it, until it occured the second time. She is acting like she normally does. Pacing around the stall with tail held up, nibbling at the hay, standing and switching legs; then repeat.