Just informing peeps they do indeed lvl up after 30 minutes of following you around (cant be mounted on them) and at 800+ loyalty.... sadly enough though i think every level they gain it adds +1 more pet points to have them T.T.... will have to make sure on the next lvl up of course, but ill let every1 know whats up after a bit more time goes by for the levels :)
EDIT: Its every 4-5 levels that adds +1 pet point to use the pet thats leveling (i think for a jungle horse, by lvl.100 it would be a total of 35 pet points roughly (WITHOUT herding)
EDIT 2: Pets do NOT level up if your character doesnt have Taming
EDIT 3: Herding decreases maximum pet point penalty for having multiple pets at once
EDIT 4: As far as i know, the ONLY stat to go up as you lvl up is the pets HP and Skill Damage (skill damage may be a combination of level+strength, but from my tests i can say 100% for sure its based off of level of pet at the least)
EDIT 5: Animal Care lowers the time it takes to level pets up (effectively at 100 AC it would only take 15 minutes instead of 30 with 0 AC)