this is such a very sad situation, i do wish both doggies a speedy recovery, take heart, if they have got rid of the cancer, bruno will be fine i am sure, i have seen many dogs and even a cat survive many long years with 3 legs, and they can sprint really fast too considering.
I know its been a tough time with lots of bad news, but hopefully with all the pet talk prayers they will sail through, heres hoping, hugs and postive thoughts to you.