Pain in right knee only. She be treated?

Around 10 months back, my mother had impact on knee due to some stray dogs collided with her from right side during their fight when she went for morning walk. She couldnt walk for some time after this incident on that same day. Had swelling around knee region. After some home medications, her pain eased in a week or so and was able to walk with slight pain. Pain stopped completely for some time also. But from last month or so she's facing acute pain in her knees which is not decreasing. Even after some home medications like massage, its reducing for some time but again is coming back. During this for few days she had other joints pain too. She has pain in right knee only and no pain in left knee. How should she be treated?