Similar to rickets in young growing animals, osteomalacia is a disease of mature animals caused by absolute or relative deficiency of any one or combination of calcium, phosphorous and/or vitamin D. The disease is characterized by osteoporosis, weakness and deformity of bones.
Aetiology: The aetiology of rickets and osteoporosis is generally same. The predisposing factors include increase demands of calcium and phosphorous during lactation and pregnancy.
Clinical findings: Signs of osteomalacia in early stage are similar to those in phosphorous deficiency and include unthriftiness, infertility, reduced productivity and allotriophagia. Affected cattle may suffer from obstruction of oesophagus and traumatic reticuloperitonitis, lead toxicosis and botulism due to licking and chewing of inanimate objects. Fracture of ribs, pelvis and long bones, and spinal deformity such as lordosis or kyphosis can be seen. Painful condition of bones and joints is manifested by stiff gait, lameness and crackling sounds while walking. Hind limbs are severely affected and hocks may be rotated in ward. Affected cattle are reluctant to move and lie down. They are unwilling to rise, as such disease popularly known as ‘pegleg’, ‘creeper’,‘stiffs’ and ‘bog-lame’ since high yielding cows suffer more severely giving ‘milkleg’ or ‘milk lameness’ names to the disease. Affected sows become recumbent and are unable to rise. They remain in lateral recumbency or in ‘dog sitting’ posture. Fracture of shaft or neck of femur is common characteristic clinical findings.
Diagnosis: Serum alkaline phosphatase activity, and bone histology are of diagnostic value. The disease must be differentiated from chronic fluorosis, polysynovitis, arthritis and spinal cord compression. Fluorosis can be confirmed by analysis of water and feed supply for excess fluorine levels.
Treatment and prevention: Treatment and preventive measures include connection of deficiencies and imbalance in diet.