Chocolate can sicken pets, and other candy may contain the sweetener xylitol, which is toxic in any amount, so it’s best to keep pets and candy of all types well separated, says AVMA President Dr. Lori Teller. Decorations that fly, shake or make noise can frighten, as can masked strangers at the door, says veterinarian Erin Forbes. Dr. Teller, Dr. Forbes and veterinarian Michelle Wisecup say pets shouldn’t be dressed in a costume of any kind if it makes them anxious, and if you are going to dress up your pet, the costume should not impair the pet’s mobility, breathing or vision or have decorations easily chewed off.