After canine hip replacement, the effects on the material properties of the collared and collarless femoral components surrounding bone were compared. Ultrasound velocites and bone mineral densities were measured and used to calculate the changes in the axial modulus of elasticity of the cortex surrounding the implant. The results showed no difference between the collared and collarless designs for the particular fiber mesh style of implant used. Significant decreases in velocities were noted after four months of implantation for both implant designs at midstem and distal locations. Bone mineral densities (using DEXA) also displayed decreased values after four months of implantation. Elasticity moduli calculated from the ultrasound velocites and DEXA densities were consistently less after four months of implantation when compared to acute implantation.