Tibial bone density, cross-sectional geometry and strength in Finnish pet rabbits: a peripheral quantitative computed tomography study.

Rabbit bones are brittle and prone to fissure formation. Radiographs of very young and old rabbits are often indicative of decreased bone density. The aim of this study was to investigate the tibial bone parameters in pet rabbits, and their association with age, sex, castration and dental disease. Eighty-seven (43 female/5 spayed, 44 male/19 castrated) pet rabbits (mean age 2.6 years, range 0.3-9.3 years) of various breeds were studied, of which 37 had dental disease. Right tibiae were scanned with peripheral quantitative CT at the distal (4percent) and mid-shaft sites (50percent of the tibial length). Analysed bone parameters included the total cross-sectional area, cortical bone area and density, trabecular bone density and strength-strain index. The mean diaphyseal cortical density was high (about 1400 mg/cm) in comparison to many other species. Within the studied age range, age was weakly but positively associated with diaphyseal cortical density, with the juvenile rabbits clearly showing the lowest values. There was no tendency for age-related decrease in trabecular or cortical bone density at least up to six years of age. Neither were sex, castration nor dental disease associated with decreased tibial bone density.