This study was performed to evaluate cortical bone strength in dogs using a quantitative ultrasound measurement device. In this study, 16 clinically healthy dogs with no lameness underwent measurement of the ultrasound propagation velocity of cortical bone (namely, speed of sound [SOS]) at the radius and tibia. Additionally, computed tomography examination with a calibration phantom was performed in 10 dogs. We calculated the bone mineral density (BMD) and Young’s modulus from the computed tomography data using bone strength evaluation software. SOS, BMD, and Young’s modulus were statistically compared between the radius and tibia. In addition, we examined the correlation between SOS and BMD and between SOS and Young’s modulus. We also examined the correlation between SOS and age in the 13 dogs whose age was known. BMD and Young’s modulus were not significantly different between the radius and tibia, but SOS was significantly different (P<0.05). Moreover, SOS and BMD showed a positive correlation in both radius and tibia. Similarly, SOS and Young's modulus showed a positive correlation. In addition, SOS and age showed a strong positive correlation (radius: r=0.77, P<0.05, tibia: r = 0.83, P<0.05). Our finding that SOS of the radius and tibia cortical bone was correlated with BMD and Young’s modulus indicates that quantitative ultrasound can be useful for evaluating cortical bone strength in dogs.