ABSTRACT
Nutritional secondary hyperparathyroidism and rickets (collectively referred to as metabolic bone disease) are underlying factors behind many of these problems. Rickets is a metabolic bone disease in growing animals caused by a vitamin D3 deficiency. Nutritional secondary hyperparathyroidism is commonly seen in both juvenile and adult birds fed a diet that is either calcium deficient or has an excess of phosphorus (or both). Early recognition and correction are important; once skeletal ossification occurs, conservative techniques such as splinting or hobbling are unlikely to be effective. Very young birds can have their legs hobbled into a normal position in order to guide the leg into a normal position during growth. In precocious chicks, leg rotation may occur for a range of reasons including insufficient exercise, high-energy diets, trauma and heated flooring. Corrective surgery, in the form of derotational osteotomies, is the treatment of choice, but it must be done sooner rather than later.
