I’ll never do immiticide again. Where I live, most of the dogs we had come through rescue were positive, so we had a fair few treated with immiticide.
The last one was extremely ill from the treatment and then nearly died when given the microfilaricide after treatment. The vet didn’t pre-treat with doxy, though, so that may’ve contributed. Anyway, the vet who gave him steroids and pulled him through told me he recommended slow-kill. His theory is that HW have evolved to be less immediately lethal to their hosts, while the same cannot be said of arsenic.
Now this was some ten years ago. I’m no longer in rescue and haven’t had occasion to treat a dog since then.
But as for the confinement, I kept my last one confined on my enclosed back porch, which is probably 6x12, for four weeks and leash-walked him. Tried not to expose him to anything that would get him excited. If I only had one dog, or only old dogs who wouldn’t engage in play, I’d probably just keep the dog in the house and leashwalk him. You don’t have to keep them immobile, but you don’t want them running, jumping, or barking excessively. Nothing that elevates their respiration/heart rate.
BTW, all the dogs I treated with immiticide did go on to live long healthy lives afterward. My last one died of osteosarcoma this past September, ten years after the HW treatment.