Ok I'm going to be the odd one out and disagree, sorry.
I do them separately, just in case one was ill, caught an infection or whatever could go wrong. That way all my attention could be with that one.
Mind you I've had 15 ferrets, (25) numerous rabbits, 3 cats, 8 dogs spayed or neutered over a 35 year period and only ever had one case of something going wrong.
__________________ Caleb   Pippi |