Facts for Case Three: Foal is lame in hind right hind fetlock. From the history we know that the mare stepped on the foalÕs leg. This is a thoroughbred foal that is only two weeks old. There are no other problems reported other than the unilateral hind limb lameness. The foal has not been vaccinated or dewormed, but this is not unusual as most foals do not receive their first deworming until four weeks of age and their first vaccination at 12 weeks of age (colostral immunity does not interfere with vaccintion until around 12 weeks post- partum. Temp. is 101.8 degrees F, pulse is 60 and respiratory rate is 52. Foal is toe touching lame on right rear limb but all other systems appear normal. The foal resents palpation of the fetlock area. No foreign bodies are found, and there are no abnormalities noted via use of a hoof tester. No instability or crepitation is noted on palpation. There is soft tissue swelling with pitting edema starting 12 cm proximal to the fetlock and continuing just distal to it.