In 2014, I wrote about Shaddow, our rambunctious 18-month-old tuxedo cat and our concerns about his safety at Christmas time. I worried that he would eat something harmful or knock over the tree and break ornaments. I remember that he played around the tree and slept under it, but there were no dire events or emergency vet visits. Today Shaddow is 11½ years old and far more dignified and too lazy for such childish activities. He and his 8-year-old brother, Orlando, still play in the Christmas boxes and like to tear up tissue paper, but we have had safe pet Christmases for many years.

We had experience with a naughty kitty. Our beloved Bilbo Baggins knocked over the Christmas tree at least once every season. Wooden ornaments saved us from a mess of broken glass. Bilbo munched my Christmas cactus (Schlumbergera russelliana, formerly S. bridgesii) down to a nub every year, savoring each tender, delicious blossom. Fortunately, Bilbo never demonstrated adverse effects from eating the ca...