Evaluation of the effect of tamoxifen citrate on model of osteoporosis in dog: biomechanical and histopathological studies

The effect of tamoxifen citrate on bone mass in immobilization osteoporosis was studied in 10 dogs.Osteoporosis was induced by fiberglass cast immobilization of the right hind-limb for 28 days, while the lefthind-limb served as a non-immobilized control. Five dogs received tamoxifen citrate (1.5 mg/kg per os) once daily for 28 days; five dogs received no treatment. All dogs were euthanized on day 28 and tibiae wereharvested. Bone biomechanical properties and microscopic structures of tibiae from casted and uncastedlimbs were studied. Significant differences in the percent of decreased values of examined mechanicalproperties were found between untreated and tamoxifen-treated dogs. No remarkable histopathologicalchanges indicative of osteoporosis were detected in the tibiae of casted limb of tamoxifen-treated dogs. These findings indicated that short term tamoxifen therapy may have promising effects on prevention ofosteoporosis in dog.