Black Cats and Howling Dogs: Halloween Hazards for Pets

Halloween is a time for people to eat, drink and be scary, but it can turn truly frightening for pet owners. Two MU College of Veterinary Medicine (CVM) faculty members offer tips on how to minimize the trouble that treats, visitors and costumes can bring to pets.

“The best way to avoid pet injuries at Halloween is to make preparations and take general precautions,” says Elizabeth Easley, DVM, a clinical instructor with the Small Animal and Emergency Critical Care Section. “Keep your pets indoors in a safe place. Make sure that dogs and cats can’t dart out the front door when you open it for trick-or-treaters. If a dog gets frightened and runs out of the house, it could be hit by a car, which might necessitate coming in for an emergency visit or, potentially, a hospital stay or even surgery.

“If you have a pet that is fearful of the doorbell, or of people in scary costumes coming to the door, keep the pet in their kennel, or in a back bedroom or somewhere safe for them, away from the noise and activity,” Easley says. “It may be comforting to have the TV or some white noise on, and have their favorite bed or blanket so they have some comfort items that make them feel more secure. Don’t leave pets out in the backyard by themselves, where they might get lonely, scared, or accidentally get loose.

“If you are taking your pet with you as part of trick-or-treating, make sure they stay on a leash and that they have a collar with their identification,” Easley says. “Make sure their identification is correct with your current address and phone number, so if they do happen to get away from you, it’s easier to get them back.

“If you’re putting a costume on your pet, make sure you try it on them in advance of Halloween, and that it’s not restrictive for them. It should not limit their ability to breathe, see or move,” Easley advises. “Make sure they are safe and feel safe. Some pets get so anxious, they may even benefit from anti-anxiety medication. With the constant ringing of the doorbell, and strangers in costumes, just do some advance thinking about your own pets and things you can do for their safety.

“If a dog ingests foreign material — by chewing up a costume, mask, makeup or home decoration — that could result in just a really bad upset stomach with vomiting and diarrhea, or a foreign-body obstruction that could require veterinary care,” Easley says. “Glow sticks could be a potential hazard for a pet around Halloween. These might be used as a costume prop or for guiding kids around the neighborhood. Dogs might think they look like chew toys. While not technically toxic, if a dog bites into a glow stick, the material inside could be really irritating, make them paw at their face, drool a lot, or even foam at the mouth.

Toxic is the raison d’être and second language of Tim Evans, DVM, PhD, DACT, DABVT, associate professor in the Department of Veterinary Pathobiology, and Toxicology Section head of the CVM’s Veterinary Medical Diagnostic Laboratory.

“Probably the primary toxicant for our small animals at Halloween is going to be the various types of chocolate,” Evans says. “The toxic compounds in chocolate are what we collectively call methylxanthines, which include theobromine, theophylline and caffeine. All of those, for the most part, cause nervous stimulation or excitation. They can also potentially cause abnormalities with cardiac arrhythmias, or the way the heart beats. Those are the big risks associated with chocolate.

“Theobromine, probably the most toxic compound, has about an 18-hour half-life,” Evans says. “What that means is that it keeps circulating in the body, so if an animal gets a huge dose of chocolate, it may be three to four days before the animal is completely normal again.

“The important thing about chocolates is the varieties we have: white chocolate, milk chocolate, dark chocolate, cocoa powder and baking chocolate,” Evans says. “White chocolate, essentially, is just sugar with minimal cocoa solids in it. Milk chocolate is when we start seeing enough that it could be a potential problem. A half-ounce of milk chocolate per kilogram of body weight, you’re going to get some very early signs. When you start getting up to 1 to 2 ounces of milk chocolate per kilogram of body weight, that’s when we’re going to start to potentially see some more serious signs. Dark chocolate has several times more methylxanthines than milk chocolate. Cocoa powder and baker’s chocolate have roughly 10 times the amount of methylxanthines of milk chocolate.

“Every year at Halloween, I get at least one call from somebody where a dog has died or is very sick, and they wonder if the animal got into enough chocolate to harm it,” Evans says. “It doesn’t take very much.  You think about a big dog eating a little chocolate, maybe that’s not going to be a big problem. If a big dog eats a whole bag of those fun-sized bars, however, that could be a problem. When we talk about toxicology, the dosage makes the poison.”

According to Easley, an emergency and critical care veterinarian, the problem with the bag of bars is not just the candy.

“Pets don’t always discriminate between the candy and the wrapper,” Easley says. “A bunch of candy wrappers can potentially cause an obstruction, which can necessitate medical care and treatment, potentially including surgery.”

Evans wants to remind pet owners of a danger beyond chocolate.

“Now that a lot of products are moving away from sugar, another potential concern is xylitol, one of the more common sugar substitutes,” Evans says. “Xylitol can be very toxic to dogs. It can cause dogs to become hypoglycemic, or having low glucose in the blood. It can even cause problems with their liver. So, the big thing is to keep human treats out of the reach of pets.”

That is a caution that Easley echoes.

“Don’t leave candy unattended around your pets,” Easley says. “If you have kids, talk to them about not sharing candy with the pets. If you want your pet to be able to enjoy the holiday alongside you, or the kids really want their pets to be able to do something to celebrate as well, purchase pet treats ahead of time,” Easley says. “They can have something special that they will enjoy, and it’s something that is not dangerous to them. As always, if pet owners have any questions, they should call their veterinarian for advice. The emergency and critical care service here at Mizzou has doctors and staff available to help you and your pet 24 hours a day.  We wish you and your pets a safe and happy Halloween.”