My 6 month old female has been very listless for a couple of days. So much that I got very worried and I took her to an emergency vet last night. He took all her signs and found everything to be stable. (thank God) She has a hard time walking and appears very tired. She does eat, does her business outside with no problems. (with an assist from me carrying her) Blood fine. Today another vet mentioned that boxers and other large breed dogs have pain in the legs due to rapid growth, known as "growing pains". She gave me medication and told me to just keep an eye on her. I've been cruising sites trying to find any mention of this but so far have not seen anything. She gets up for a bit then goes back to lay down. Any help would make me sleep better..if at all!