[Use of bone markers in veterinary medicine]

Bone metabolism can be monitored in humans and several animal species in vivo by measuring enzymes and other protein products released by osteoblasts and osteoclasts, respectively. The biochemical markers of bone formation currently in use include bone isoenzyme of alkaline phosphatase, osteocalcin and propeptides derived from the N or C terminal ends of the typ I procollagen molecule. The most useful markers of bone resorption are breakdown products of type I collagen. The oldest established method is the measurement of hydroxyproline in urine, which is not specific for bone, because it can be found in all collagen types and is also derived from diets. The measurement of collagen crosslinks, deoxypyridinoline and pyridinoline, is comparatively more specific to monitor bone resorption. Deoxypyridinoline and pyridinoline are used in human medicine for diagnosis and evaluation of bone diseases and in predicting the occurrence of fractures and rates of bone loss. The carboxyterminal telopeptide of type I collagen, which has been used in several animal species, is also a promising bone marker. This article reviews the use of different bone markers in veterinary medicine and the possibilities for diagnosing and preventing bone diseases.