#8 Preservatives on your tree
Chemical preservatives are sometimes used on Christmas trees to keep them fresh longer. The problem with these chemicals though, is that they will leach down into the water bowl at the bottom of the tree. Making the water poisonous. Water that a pet will likely keep lapping up. It is best to not use these preservatives altogether, but if you must, use a tree skirt, towel, aluminum foil, plastic wrap, or something to cover up the water bowl.