The biggest hazards to pets on Thanksgiving include:

Rich, fatty foods (turkey skins, gravy, etc,) can contribute to pancreatitis. This inflammation of the digestive gland is painful and can be serious--requiring emergency veterinary assistance.
Cooked bones can splinter and cause tears or obstruction in a pet's digestive tract.
Baking strings, if ingested, can create trouble if ingested by your pet.
Onions in holiday stuffing can lead to canine anemia if consumed by your dog.
Grapes and raisin toxins can cause kidney failure in pets.
Ingesting chocolate can kill your pet.
Caffeine and alcohol are also toxic for pets.
Keep all goodies out of reach!

Also do not forget metal turkey skewers, tooth picks, foil, and decorations... if your deep frying watch your animal around the cooker as well. Also with all the guest, give your cat a safe place to escape to if necessary and watch the little children that they are not used to dealing with. Kids can be unbearable to our furry friends sometimes. Happy Thanksgiving

Thanks for the reminders. Sometimes people forget their pets are not able to handle the trimmings and think they are "treating" their pet.