Hunters do have a dismiss command. If you are running around Shat or at the AH, just dismiss your pet. When you call him back, he will be at the same lvl of happiness.
It all has to do with lvl of food. The closer your food level is to your pets lvl, the longer he will stay happy. Also, if you are killing things your level that drop meat, feed it to your pet. He will stay happy.
Bottom line, if i was getting beat on by some big guy, and my best friend was standing back out of harms way, I would be pretty unhappy with that arrangement too. If feeding your pet really bothers you, create a warlock.