If your pet gets this talent EVERY stat limit increases by 50.
Your pet can now be trained past Epic to Mutant, where it gets a 5th ability.
I don't play the pet derby, but since this affects both derby abilities and talents you could just not give it any derby ability when the Mutant is achieved and give it a pet derby ability when Mutant is reached.
I would say you would have to train the pet another 1000 points at a cost of 8 energy each training.
I know this adds a lot of training, but the talents that are affected by the increase in stats would benefit.