Sepsis One of the hypotheses for the cause of the calfŐs leg is sepsis localized to the metacarpal-phalangeal joint. The calf was too large at birth, so it was necessary to use a FrankŐs calf jack to remove the calf from the cow. During the removal of the calf, the skin covering the metacarpal-phalangeal joint was damaged. The damage to the skin allowed the entry of bacteria into the joint. Infection of the joint is evidenced by the draining tract from the joint area that oozes purulent material upon manipulation of the leg. As the infection in the joint progresses, responding inflammatory mediators cause damage to the articular surfaces of the joint. As the amount of damage to the articular cartilage and underlying subchondral bone increases, remodeling begins to occur. The subchondral bone and the joint capsule thicken to aid in joint stability. The fibrosis which occurs with this remodeling causes a decreased range of motion which is evidenced on the physical exam with a decreased range of motion in the metacarpal- phalangeal joint and swelling of the leg. However, despite the damage caused to the leg, the sepsis does appear to be localized. If the calf does have a temperature, it is only a slight fever and could be due to stress. This, and the fact that everything else is normal including the calfŐs appetite, indicate that the infection is localized to the joint area.