My Abby pup isn't feeling well

Some of you may have seen the post I've done about my German Shepherd pups Abby and Willow. For the most part things have been great, but last week Abby started limping. She didn't hurt her leg playing, or anything like that, and then I noticed it went from her right front leg to her left. I set her up for an appointment with the vet tomorrow, I tried taking her in yesterday, but it being a Saturday, it was packed, and she couldn't be seen.

While she was out yesterday, she didn't show any signs of pain, she even got in the truck on her own with no limping. I was hoping that she would be better, but she started limping again last night. I've also noticed she hasn't been eating, and is starting to lose weight. I did some research and found it could be Panosteitis, which is essentially growing pains. It is common in fast growing dogs, especially German Shepherds, so I'm hoping that's what it is, and not something more serious.

If that's all it is, then it will not have any long term effects, and can be managed with pain meds. Nothing appears to be broken, and she has moments where she can walk, and even run without limping. I'm no Vet, so I have no idea what it may be. I just hope it's nothing to serious, and she can get back to enjoying being a puppy soon.