Glad to hear about the blood values being almost normal. I am SO glad this vet is staying on top of the pred dosage. So many many vets will drop the dosage too quickly and the dog will relapse, sometimes with fatal results. Once the values are normal, then by slowly decreasing the dosage, he will continue to improve.
Don't worry, his muscles will return and he will look normal fairly quickly. You will be surprised how quick it all comes back on.
Glad the antibiotics are still on board, they are so so important also to kick this stuff.

checking back constantly to keep up to date on you and kelso.