My dog limps badly

[mimida]

I have a 3-year-old, 60 pound mixed breed rescue dog.  He was found starving, injured, heartworm infested with lung involvement, and shot.  We have a handle on all his problems except the limping.  When we adopted him a month ago I noticed limping on his back leg.  That is gone, and he now limps very badly on his right front leg, which I didn't notice then.  He simply began to limp about two weeks ago.  Extensive x-rays show nothing in any bone or joint, though his lungs look a little dark.  A second lung x-ray showed improvement.  When I put my hands on each shoulder I feel a muscle on the left that I can't feel on his right side.  It's as though the muscle isn't there.  He was treated with prednisone and now with previcox.  His last vet appointment was six days ago. The vet said to keep him as quiet as possible and wait.   He still has a bullet in him, but it is not near the right shoulder.   I'm panicked.  What could this be?  

[mimida]

have 2 kids, I read your entry and the symptoms do sound similar.  Charlie has been on antibiotics and eats well with no fever, but I have a call in to my vet to see if there has been a blood test that would show something significant.  Since his rescue he has had three vets so the care has been a little spotty.  I hope your dog begins improving soon.  These dogs have been through so much and deserve kind, loving homes where they are safe and cared for.  -Mimi

[have 2 kids]

Has he been checked for tick bourne illnesses?    lyme disease or rocky mountain spotted fever?       You can pm me if you like.  We are going through a very similair experience right now.