Medics can indeed heal pets. BM is highly viable but obviously you are going to want different pets for different occasions. This is particularly important as a BH/BM, where you'll want to use different pets for different marks. A pet for debuff, a pet for cc, a pet for burst, dots, et cetera. Therefore, it is chiefly rich BHs who undertake to be BMs.
While BH and Medic are at face value really good BM choices, Commando and Smuggler are exceptional choices too. Additionally, I recall a very successful Hellstorm Officer back in the day who wtfbbq'd entire groups of rebel pvpers by rushing in->vortex->stomp->sfp and unleash armageddon. It was at times obscenely useful in Restuss.
If you're a medic I'll recommend a pet like the kliknik - heavy dots and high dps. Medic won't in general need a tanky pet.