HW treatment aftercare advice?

What works best is different for each dog. I've currently got a dog in my household being treated - he's an approx 3 year old Dobe pulled from animal control in DE and tested positive. I worked him up and he was actually graded as a Grade III (from I-IV is the grading, I being least amount of risk, IV being risk of death) due to heart and kidney changes. He's had his second treatment and is on week 8 of his crate rest.

For him, he is crated in a different room AWAY from us. Us being around is too much for him - he whines, cries, and flips around and I want him quiet. He's leash walked only.

However, he does have time out - he is allowed to sleep outside the crate at night in my tenants bed, he is allowed to do some clicker training in a room (INSIDE) for sits, downs and attention work. He is allowed loose in the living room as long as he lays on the couch when no other dog is around. And in his cage he gets bones, bully sticks, kongs, etc galore.

If necessary I was willing to sedate him, but it hasn't been necessary. I am clearing him for activity in 4 more weeks, as long as everything goes well.

Has the vet explained to you WHY  it is so critical to keep the activity level SO low?  If I recall Gracie's is pretty extensive (didn't I read she's actually showing a lot of 'sign' -- coughing, etc.?? or am I thinking of someone else?)
 
Heartworm are easy to kill -- seriously.  The problem is when they die it's a lot like a handful of cooked spaghetti in the heart -- that means these dead parasites lose structural integrity after they die -- and as the heart beats they break up.  Then this dead parasite material goes sailing thru the bloodstream.
 
The body has to filter that out and reabsorb it -- THAT is the big deal.  The debris can clog the kidneys and liver and cause them to shut down.  It can cause a stroke -- it can generally just plain cause things to come screeching to a halt in ways it ought not. 
 
THAT is why you gottta keep the dog absolutely completely sedentary.  And the first few weeks are the most critical.  You *must* keep her calm, cool and totally collected!  Even if you have to sedate the heck out of her to accomplish that -- it's better she sleep day after day crated than get all upset and paw and whine and be agitated.  You want to keep the heart rate minimal. 
 
I don't mean to scare you -- well, yes I do.  Often vets don't explain this.  They just say "keep the dog calm" -- but they don't tellyou how critical it is.  If you have to actually give her benedryl or something to help her relax and sleep DO IT.  When you let her out rather than 'play' you invite her up to sit next to you for petting. 
 
If you have to lower her protein intake so you aren't giving her rocket fuel with no where to burn it off -- DO IT.  Whatever it takes to keep her sedentary is really pretty darned important.
 
 

Actually Gracie's level is just about a II, she's just starting to cough and veins in her heart are just starting to show inflammation on x-ray. Back in Dec. she had no symptoms and only some slight inflammation in the lung veins. There's no microfilaria (sp?), so that's also good. I know why keeping her calm is important, yes. She will crated except for brief potty walks in the front yard (we had a small flight of stairs in the back, so we'll take her out front) and in the evenings after the girls have gone to bed she generally just lays on the couch while we watch TV, so she should be okay with that as well. I was wondering about diet, supplements and the like. That's a good point about the protein reduction, any advice on what to actually feed her? We've got a supply of new bones, and plan on stuffing the Kong, but I think toys would excite her too much.