If it is very swollen it is probably broken take it in and get it checked out if you can.
How To Tell A Difference Between A Broken Leg Or A Sprang Leg For A Yorkie Dog?
Very severe fractures can be palpated or even visualized as abnormal range of motion. Radiographs should be taken of all suspected fractures or severe sprains. This will confirm a fracture, determine the type of fracture, and affects how the fracture is treated. Have your dog examined by a veterinarian--small dogs are prone to limb fractures from traumatic injury.