Is this normal?

Three weeks ago he was attacked by a coyote and later (when we realized something was wrong) took him to the vet. He was cleaned up as best as possible, sewn back together. He had no major injuries, one of the muscles in his leg was slightly damaged. That was the worst of the damage. A week later I took him back to the vet and the drain was removed. The following week, back to the vets to have the stitches removed. Well turns out that he had a huge fluid build up (drain was removed too soon), but that was the least of his problem. Turns out a lot of his fatty tissue had actually died. So another surgery to removed all the dead tissue and another drain.

Here we are 9 days later, he is still draining. He was just on my lap and as I held him, he was quivering from head to toe. He appears to be happy, is eating well, and plays with some of the toys. All this as best he can with a cone on.

Should I be concerned? or is this just normal in the healing process?