Attached is the new official UO wiki post. It contains all the information on the new publish 97 that allows you to train pets. Also what each properties weights are and what the gumps look like.
https://uo.com/wiki/ultima-online-wiki/skills/animal-taming/animal-training/
https://uo.com/wiki/ultima-online-wiki/skills/animal-taming/animal-training/