I had a lab that was treated for heart worm; he had it when I adopted him. It's true that he had more body fat than your dog, but the treatment was rough on him. It was a long time ago, back when dogs were being treated with arsenic. Maybe things are better now.
Even Robin can chime in on this. I do live with two galgos and go to Spain every six months or so to volunteer at FBM Yes, intellectual stimulation is important if you have an active dog.
Even better, you can adopt super active, super smart, super curious, super uninhibited, super crazy Xavi the galgo. He's only an hour away! Would you trust this face???
Just kidding! Today, anyway
Everybody is different. Osteo does not go away and maybe she wanted to save her dog from tremendous pain. I've lost all of my greyhounds to osteo and was always told that no matter how much of their pain we witness, the dog is experiencing much more than we will ever see.