Epiphysitis is a lack of proper mineralizing or calcifying of the matrix tissues that form on the ends of the long bones, generally on the cannon bone. Rather than hardening into solid bone, these growth areas stay soft and spongy, and soreness and swelling are quickly apparent. Osteochondrosis Dissecans is the lack of proper cartilage growth in the joints of young performance horses.
Bone cysts develop at the growth center of the joint.
As a young horse's training increases, he may actually fracture a ball and socket joint, most frequently a stifle or hock. Wobbles is a malformation of the cervical vertebrae caused by abnormal cellular growth at the bone growth center of the vertebrae. In essence, this growth constricts the opening through which the spinal nerves run through the spine. Contracted tendons is another malady whose suspected cause is abnormal bone growth. A foal with this problem will stand up unusually straight on its fetlocks.