Nostalrius Begins - Quality wow vanilla realm (1.12)

I have a terrible level 52 cat that is struggling to keep up with me, I'm level 56 and nearing 57 and my pet is constantly falling behind. He cannot hold aggro and barely hits the mobs I'm fighting, any tips on how I can powerlevel him? Googling the issue just gives me results of that awful pet battle system in retail..

Kill elites that're of xp range to you for faster/better gains for pet. Otheriwse, kinda out of luck.