Who knew that trick-or-treat time would become a pet parent’s favorite holiday? My Inbox has been flooded with animal costume contests, some that you enter in pet person and others that just require a photo.

PetSmart even has a “Howl-O-Ween” Central section of its Web site – and costumes are on sale right now. Local PetSmarts already had their in-store contests and pet parades, and the photo competition ended last week. The grand prizewinner was this tabletop pup. But I say extra credit should have been given to whoever was able to get a cat into Elizabethan finery; this was the only feline among the finalists.

The PetSource.org costume photo contest still is going on, if you want to get in on the action. Click here to enter. The competition ends on Friday. The winner gets a buncha pet swag, plus $1,000 to give to the local humane society or shelter of his/her choice.

So: Are you trick-or-treating with your pet this year? What’s your costume? I noticed there are some companies selling owner-and-pet ensembles, so you can go as a matching pair.

Here are some things to remember to help your dog or cat have a Happy Howl-O-Ween:

* Don’t feed candy to dogs or cats – especially chocolate or raisins, as these foods can be toxic to animals.
* If you go trick-or-treating outside, keep your pet on a leash and scan the ground for dropped candy that might be scarfed up.
* Keep decorations away from pets.
* Put your pet in a secure spot inside if trick-or-treaters will be coming to your door.

And be careful when picking out your party animal’s outfit. The pet-purrfect Halloween costume is:

* Roomy but does not drag on the ground in a way that would trip your pet.
* Has no parts that could be easily chewed off and swallowed.
* Made of flame-retardant material.
* Should not have tight masks or capes that could choke your pet.

Thanks to the Animal Medical Center in New York City and VPI Pet Insurance.