Hi Paul
Here is some info I found for you from a walkthrough on gamefaqs for the Xbox 360 about your pet. I hope it helps.
Cathy

Your pet is not just there for looks, it can fight alongside you and even cast
spells if you teach it some. In the inventory menus, you can set the pets mood
by pressing start and choosing from one of three stances: Aggressive, Defensive,
& Passive. Aggressive pets will attack any creature in there line of sight and
pursue them if they flee. Defensive pets will attack only if they are attacked
first and Passive pets will not attack at all.
*If your pet gets too low on health it will flee, fleeing pets run wildly and
aimlessly and do not attack or cannot be sent to town. You can heal fleeing
pets or just wait for them to calm down a few moments after all enemies are
dead in the immediate area.
*You can dump unwanted items into your pets inventory and send it to town to
sell everything it is carrying. After a short time your pet returns with your
gold and you never had to take a break from the action! To send your pet to
town,open the inventory menu (back button) and then the pet menu (start button)
and then press Y. You receive a confirmation that your pet is off to town, and
it will sell all unequipped items in its pack.
*You can equip your pet with three trinkets: a necklace and two rings
*You can transform your pet into other creatures temporarily and permanently
by feeding it fish. Permanent transformations are permanent unless you feed
your pet another transformation fish (even a temporary one). So be aware that
you can lose a permanent transformation as it will change back to the wolf,
lynx, or Chakawary after the new transformation is done.
*Your pet can have two spells learned at any time and it will cast them without
any real reason or set parameters but it will cast spells like summons often
so those are good to give it. To teach your pet a spell, move a spell scroll
to the pets inventory with X and then use it in the pets inventory with A. If
your pet already has two spells and you teach it a third, you have to choose
one of the current two to delete permanently. You cannot force pets to cast
spells, they do it on their own.
*Other fish can be found that pets can eat to provide damage or item find
bonuses and the like. If you feed your pet fish that grant item or gold find
chances be aware that the pet must kill creatures for those bonuses to take
effect, not you.