Bent leg is a form of rickets and is due to a malfunction of bone metabolism during growth. It occurs during the rapid growth phase of the lamb, usually between 6 and 12 months of age. It occurs primarily in rams, but can occur in ewes. It is more common in Rambouillet and related breeds. Similar conditions occur in cattle, horses, dogs, poultry, and people.
It can be prevented by 1) feeding balanced rations; 2) avoiding the use of too much high energy or high protein feeds (rapid growth and nutritionally “pushing” animals for growth is a factor in all species for increased incidence of rickets); 3) providing a calcium to phosphorus ratio of at least 1.5 to 1; 4) supplementing the ration with 300 IU of vitamin D (per 100 lbs of body weight per day); 5) providing adequate magnesium; 6) shearing young rams in early winter to allow more skin surface for vitamin D conversion; and 7) providing housing that provides good exposure to sun during the winter.