here are some places a friend suggested to me:

Pet lvl 54
Got to South Pole and fight with wolves. Wolves are lvl 60-73 so with lvl 54 pet, equips won't be broken. Stay here until lvl 66

Pet lvl 66
With lvl 66 pet you can train at china without the possibility to break the pet's equips. Pandas are lvl 85-86.

Pet lvl 70
You can go to Clive's Cave, and if you go down, you will find a room with full of pirates. there you can trin your lvl 70+ pet with equips. Pirates are lvl 84-89.