Hypothesis 3 Ð Asymmetric Growth of the Metaphysis/Epiphysis The foal presented in this case is lame on its right hind leg. Prior to physical exam, the foal is toe touching. After the physical exam however, the foal seems to become more lame and will not place her foot on the ground. During the course of the physical exam, we determined that the foal is painful in the fetlock joint and pitting edema is present. There is no crepitance or instability present in the fetlock joint, and the foal does not resent hoof testers either. One possible rule-out is asymmetric growth of the metaphysis or epiphysis. The major cause of asymmetric growth is trauma to the growth cartilages in the form of pathologic compressive forces. The dam stepping on the foal would qualify as a pathologic compressive force. Another possible cause of the asymmetric growth is intrauterine malpositioning. At this point we do not know if there was any difficulty during parturition, or if this lameness has been present since birth. Either of these incidences of trauma to the foal essentially causes the angulation of the limb to worsen. (Under normal physiologic compressive forces occurring during walking, running, etc., the limb straightens.) Infection of the physis which could occur with sepsis might also result in the asymmetric growth. This is supported by the inflammation and pitting edema found during the physical exam.