my 3 month old puppy's leg makes a cracking noise when he walks / when i pick him up / stretches / scratches. What could cause that? Does that mean his leg got hurt? He doesnt show any signs of pain.
Cracking noises from a puppys leg is not normal. Take him to see your vet and let him diagnose the problem. He may not be in pain right now, but he may suffer later in life.
If he's 3 months old, its more that likely growing pains. Happens to most dogs. I'd have the dog checked out by the vet to make sure it isn't anything worse then growing pains.