Help your kitties enjoy the holidays safely by keeping them away from potential problems during this special time.
Food/Beverages: All alcohol is toxic to cats and should never be given to them. Homemade eggnog is rich enough to cause an upset tummy even if it isn't the homemade version potentially contaminated with Salmonella bacteria. "People" food is a bad idea in general because of its tendency to cause vomiting/diarrhea. And put that turkey wishbone in a safe place to avoid choking a sneaky cat on the prowl. After people finish the big meal, a small (1 tbsp) snack of roast turkey breast is okay for our feline friends in most cases.
Holiday Plants: Poinsettias, while not actually poisonous, contain a highly irritating sap which can cause vomiting so severe it can require days of hospitalization so keep them out of reach. Water in Christmas tree stands contains pine resins which can cause liver damage - keep it covered securely so kitty can't drink it. Holly, mistletoe, and lilies of all kinds are extremely poisonous to cats.
Potential Foreign Bodies: Tinsel and ribbons pose not just a choking hazard, but most importantly can tangle in and slice up a cat's intestines if swallowed, causing fatal injury. Never allow a cat access to any of these "linear foreign bodies". Styrofoam, "angel hair", and small ornaments can cause intestinal blockage or injury. Ornament hooks and thin glass ornaments can cause mouth lacerations if chewed on and deadly injury if swallowed.
Toxins: Old bubbling lights and decorative fireplace salts contain very toxic chemicals. If you have candles burning, keep your matches where the cat cannot chew on them. Potpourri oil simmering pots are dangerous because the liquid is caustic - we treated a cat with terrible chemical burns in its mouth a few years ago due to licking at potpourri liquid.
Gifts: Give your cat safe toys such as small mice, plastic bell balls, crinkly mylar balls, small stuffed fabric objects, and of course catnip! Avoid toys with tiny loose parts, any linear material longer than 2 inches, or toys made of sisal rope. If you give kitty a fishing pole-type toy with fish (or mouse) attached, remember that this type of plaything is for adult-supervised play only, and must be stowed securely where kitty cannot get at it afterwards because the "fishing line" is just another linear foreign body waiting to happen.
Don't let all these potential hazards scare you - it is possible, with a little advance planning, to have a very merry Christmas, and a happy and safe one for kitty!