Make sure your pet is properly identified (microchip, collar and ID tag) in case s/he escapes through the open door while you're distracted with trick-or-treaters;
Keep lit candles and jack-o-lanterns out of reach of pets;
If you plan to put a costume on your pet, make sure it fits properly and is comfortable, doesn't have any pieces that can easily be chewed off, and doesn't interfere with your pet's sight, hearing, breathing, opening its mouth, or moving. Take time to get your pet accustomed to the costume before Halloween, and never leave your pet unsupervised while he/she is wearing a costume;
Keep glow sticks and glow jewelry away from your pets. Although the liquid in these products isn't likely toxic, it tastes really bad and makes pets salivate excessively and act strangely;
If your pet is wary of strangers or has a tendency to bite, put him/her in another room during trick-or-treating hours or provide him/her with a safe hiding place;
Keep your pet inside.
Attention, animal lovers, it's almost the spookiest night of the year! The ASPCA recommends taking some common sense precautions this Halloween to keep you and your pet saying "trick or treat!" all the way to November 1.
No tricks, no treats: That bowl of candy is for trick-or-treaters, not for Scruffy and Fluffy. Chocolate in all forms—especially dark or baking chocolate—can be very dangerous for dogs and cats. Candies containing the artificial sweetener xylitol can also cause problems. If you do suspect your pet has ingested something toxic, please call your veterinarian.
Popular Halloween plants such as pumpkins and decorative corn are considered to be relatively nontoxic, but they can produce stomach upset in pets who nibble on them.
Wires and cords from electric lights and other decorations should be kept out of reach of your pets. If chewed, your pet might suffer cuts or burns, or receive a possibly life-threatening electrical shock.
A carved pumpkin certainly is festive, but do exercise caution if you choose to add a candle. Pets can easily knock a lit pumpkin over and cause a fire. Curious kittens especially run the risk of getting burned or singed by candle flames.
Dress-up can be a big mess-up for some pets. Please don't put your dog or cat in a costume UNLESS you know he or she loves it (yup, a few pets are real hams!). For pets who prefer their “birthday suits,” however, wearing a costume may cause undue stress.
If you do dress up your pet, make sure the costume isn't annoying or unsafe. It should not constrict the animal's movement or hearing, or impede his ability to breathe, bark or meow. Also, be sure to try on costumes before the big night. If your pet seems distressed, allergic or shows abnormal behavior, consider letting him go au naturale or donning a festive bandana.
Take a closer look at your pet’s costume and make sure it does not have small, dangling or easily chewed-off pieces that he could choke on. Also, ill-fitting outfits can get twisted on external objects or your pet, leading to injury.
All but the most social dogs and cats should be kept in a separate room away from the front door during peak trick-or-treating hours. Too many strangers can be scary and stressful for pets.
When opening the door for trick-or-treaters, take care that your cat or dog doesn't dart outside.
IDs, please! Always make sure your dog or cat has proper identification. If for any reason your pet escapes and becomes lost, a collar and tags and/or a microchip can be a lifesaver, increaing the chances that he or she will be returned to you.