The pilot reported that the airplane impacted a deer during the landing roll at night. The airplane's propeller struck a deer, which subsequently struck the right main landing gear assembly. The pilot taxied the airplane to the ramp and he exited the airplane. The following morning the pilot assessed the damage and decided to fly the airplane around the pattern. Upon liftoff, the lower strut assembly from the right main landing gear, including the wheel, separated from the airplane. The pilot continued the flight and landed the airplane at another airport.