My dog has Pano and I'm wondering if you can give any advice or insight to the situation before I bring him to the vet.

I have a 13 month old GSD half German/American blood lines. His parents are both champion show line dogs. The other day during out fetch the ball session Zeus began to favor his left leg. His appetite is unchanged and he does not have a fever however, I have noticed there is now some limping. I called the breeder and she took a look at him. She has over 35 years experience raising and breeding champion GSD's. She explained to me that it appears to be "Pano" and to simply keep an eye on him and limit some of his stressful activities until the symptoms subside. She also explained that the "growing pains" of Pano may switch from one leg to another at a later date and I may try giving Zeus a buffered aspirin every other day to help alleviate the pain. My question is do you know more about canine Panosteitis and what else I can do to give my dog relief. Zeus is a wonderful dog and my heart is breaking just to look at him limping around even to take a few steps to the yard to relieve himself. I want him well again and any advise I can get would be great. I have an appointment with the Vet in 2 days. Hopefully, you can give me some more information before we make his appointment. Thank you kindly.