It takes about a week for a cat to recover from a sprained leg. The specific time depends on whether the sprain is serious. When a cat sprains, it needs to be supplemented with nutrients and calcium. You can also apply heat to the cat, which is more conducive to the recovery of the sprain. If the sprain is serious, it may not be able to heal on its own, so it is best to go to the pet hospital for a check-up to confirm that it is not injured. bones or joints to avoid delaying the condition.