It sounds like your dog may be experiencing muscle atrophy (shrinkage). This occurs with disuse, myositis (muscle inflammation), nerve disease, or cancer. This dog needs to be examined by a veterinarian to diagnose this condition.
Is there anything the vet gave your dog? My dog seems to have the same but is still eating and walking, just old now.
Thanks. I did that yesterday and that is what they said. Thank for the help