Noise and Strangers
The stress of excited children ringing the doorbell and the strange looking costumes they're wearing may frighten your pet. This can cause aggressive behavior in even the most calm animals so it's a good idea to keep your pets in a quiet area of your home until the excitement is over.
If a pet wears a costume, make sure it is not constricting, causing your pet to trip, or blocking its vision. Do not force a pet to wear a costume if it demonstrates discomfort.
Candy & Chocolate
Candy, especially chocolate, is toxic for animals and can cause vomiting, restlessness, heart disturbances, and even death. Ask kids not to share candy with pets and make sure that Halloween candy is put safely out of reach.
Don't leave pets outside on Halloween. Many animals disappear as pranksters and those with darker intentions tease, abduct, torture, or even kill pets.
Be especially watchful of black cats, which are frequent targets of cruel activities on Halloween. Try to keep black cats inside for the week of Halloween. Many animal shelters make black cats unavailable for adoption the week before Halloween because of black cat abuse.