If you're ok with it, I'd wait till he acts like he's uncomfortable. That's so rough. We had to put a cat down last year and I hated to do it. It still bugs me and every once in a while Sydney mentions him It always makes me sad.
I just read a memo about the future of IT here...and in a nutshell my job is ok for a year at least, but they are moving toward a new structure and will cut IT positions from 2011-2015. Ugh.