To be honest, I'm a little surprised by the responses. While, yes, a lot of the time our pets are very good at avoiding or massively mitigating the damage they receive so that it doesn't matter. That said, there are mechanics that can cause a pet to die unless we completely turn off around 15% if I remember correctly of our DPS off (more if we're BM) and call them to our side - but we can keep that if a few heals were thrown our pet's way every now and then.

One example off the top of my head is a lot of the Trash in Firelands - There were effects that would kill our pets after about 10 seconds or so, even with mend but constantly on them. If a healer could have thrown a heal its way every now and then, it would have been fine - but otherwise, it dies.

Yes, these situations are far and few between, but the point stands: If a DPS can do more damage with a healer healing a pet, and the healing isn't being prioritized over actual raiders, then it behooves the entire raid for the healer to heal the pet, and the pet owner to be sure there isn't another way to get the same DPS without the damage. As long as this is happening, the situation is being optimized. This goes for all pet classes too, not just hunters, though hunters gain the most DPS from their pets.