Variable. Check motion and sensation. If any deficit go to your doctor.
Check sensation. Cat bites can develop serious infections quickly. If you have persistent redness, red streaks up your arm, or increasing pain, seek medical care quickly. If there is no sign of infection, you can check for nerve damage by testing the feeling in the skin past the area of bite. If you have an area that is numb, a nerve could be bruised, or less likely cut.