title: Experimental investigation of bone mineral density in Thoroughbreds using quantitative computed tomography.
abstract: Bone mineral density (BMD) is one of the indications of the strength and health. BMD measured by quantitative computed tomography (QCT) was compared with that measured by dual energy X-ray absorptiometry (DXA) and radiographic bone aluminum equivalence (RBAE). Limbs were removed from horses that had been euthanized for reasons not associated with this study. Sixteen limbs (left and right metacarpals and metatarsals) from 4 horses were used to compare BMD as measured by QCT with those measured by DXA and RBAE. There was a strong correlation between BMD values measured by QCT and those measured by DXA (R(2)=0.85); correlation was also observed between values obtained by QCT and those obtained by RBAE (R(2)=0.61). To investigate changes in BMD with age, 37 right metacarpal bones, including 7 from horses euthanized because of fracture were examined by QCT. The BMD value of samples from horses dramatically increased until 2 years of age and then plateaued, a pattern similar to the growth curve. The BMD values of bone samples from horses euthanized because of fracture were within the population range, and samples of morbid fracture were not included. The relationship between BMD and age provides a reference for further quantitative studies of bone development and remodeling. Quantitative measurement of BMD using QCT may have great potential for the evaluation of bone biology for breeding and rearing management.
authors.affiliation: Obihiro University of Agriculture and Veterinary Medicine, Hokkaido 080-8555, Japan.
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Yamada
authors.affiliation: Hidaka Training and Research Center, Japan Racing Association, Hokkaido 057-0171, Japan.
authors.forename: Fumio
authors.initials: F
authors.lastname: Sato
authors.affiliation: NOSAI Hidaka, Hokkaido 059-3105, Japan.
authors.forename: Tohru
authors.initials: T
authors.lastname: Higuchi
authors.affiliation: Obihiro University of Agriculture and Veterinary Medicine, Hokkaido 080-8555, Japan.
authors.forename: Kaori
authors.initials: K
authors.lastname: Nishihara
authors.affiliation: Obihiro University of Agriculture and Veterinary Medicine, Hokkaido 080-8555, Japan.
authors.forename: Mitsunori
authors.initials: M
authors.lastname: Kayano
authors.affiliation: Obihiro University of Agriculture and Veterinary Medicine, Hokkaido 080-8555, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Sasaki
authors.affiliation: Obihiro University of Agriculture and Veterinary Medicine, Hokkaido 080-8555, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Nambo
keywords: Thoroughbred; bone mineral density; dual energy X-ray absorptiometry; quantitative computed tomography; radiographic bone aluminum equivalence