Kim, a larger tree, well anchored, would be great for the pets. Cats would enjoy dangly bits hanging from branches as well as the climb to the top. Dogs could find biscuits attached to branches or under the tree. A cushy mat around under the tree provides a shelter in which a domesticated animal can sleep and dream of wilderness adventure.

Just keep all ornaments natural and unbreakable and you'll be fine. There will be a bit of a mess to clean up but it shouldn't be too difficult if you use a wide blanket or tarp to protect the floor.

Christmas is for animals too.

Catrin, our local animal shelter asks people to come in and play with their animals as much as possible. They provide leashes so people can walk the dogs and a play area for people to pet and play with the cats. Maybe something like visiting the local animal shelter on or near Christmas would be a possible addition to your holiday celebrations.