My GS is just over a year old and is limping again. Her limping can last for like a week or more. She signals no pain and she just keeps her back leg up but will still try to jump. This is probably the 6th time since she was about 8 months old. Can your dog grow too fast from too much protein and cause growth pains or what? Her previous dog food made her sick a few weeks ago and now she's on a brand she likes but since limping again she doesn't touch it when given so it's like she gives in many many hours later because she's hungry. I do plan on getting x rays and a few other things done soon.