Spring is beginning to bloom as the animals begin to run wild. First on the doctor's list is mini-horse, Mateo, whose hormones have kicked in, making him go wild for the mares. The solution is to castrate Mateo to lessen the testosterone, but this turns out to be no ordinary castration. Then, Jezebel the cow is in distress and unable to birth her calf. Dr. Pol and Charles discover that she has milk fever and if not treated quickly enough, could slip into a coma, causing her and her calf to die.