Using Pincos my vet macro is . . . .
In the 1st box I have "Target Nearest Follower" and then I dragged my bandages (I always use the same color, so even if I run out I do not have to adjust the macro) in the 2nd box and have them set for "Current Target"
This works for me as I don't target what my pet is attacking, I have the mobile bar pulled off of it. This will not work that well for you if you like to keep your pets target targeted.