To veterinarian Lisa Murphy, it's a familiar scene: "You come home, there's a mess, the dog has thrown up. Maybe initially you don't think much of it because the dog did the same thing with the trash last week. You clean all the mess up, shoot the dog a dirty look, and move on."

But what if there's more to it than that? During major holidays, people get distracted. All sorts of intriguing - perhaps even edible - things get left around. Dogs will be dogs. And cats will be cats. Maybe it's not just a routine "mess."

If that dog doesn't get better, Murphy said, "it's time to call the vet."

Murphy, associate professor of toxicology at Penn Vet, and Kenneth Drobatz, chief of the emergency service at Penn's Ryan Hospital, recently weighed in on how to keep your pets safe during the holidays.

Dr. Murphy, people always worry about poinsettias, mistletoe, and chocolate. Should they?

This time of year, people are so busy, and you turn around and see your pet chewing on a leaf and the first thing that comes into your mind is that you've just killed your pet for the holidays. But poinsettias really aren't so bad. For most pets that might eat a leaf or a petal, it's going to cause mild stomach upset. They might throw up. Their appetite might be off. Restrict their access to food or water for a few hours and let their stomach settle down. If that doesn't do it, then, yes, call a vet.

With mistletoe, the most toxic part is the berries, the part that drops off of the nice little arrangement you've just bought. However, very often some retailers actually remove the real berries and replace them with plastic berries - probably because of the risk to children. So at that point, it's more of a foreign-body risk. But for the real berries, it's usually just a case of vomiting, lack of appetite for a few hours, etc. For any animal, the risk of prolonged vomiting or diarrhea is becoming dehydrated. This can particularly be a problem in very young or very old animals.

For chocolate, the type of chocolate makes all the difference. The toxic compound is caffeine, but there's also a related compound called theobromine. In general, the darker and richer the chocolate, the higher the concentrations. The issue with caffeine and theobromine is - like with espresso in humans - they can get hyperactive and their heart rate can increase. In serious cases, they can have seizures and cardiac effects. Caffeine usually only stays in your system for a few hours, but theobromine can hang around for a longer period of time, meaning our pets can be at risk for serious symptoms.

By the way, it's usually in dogs. Cats are a little smarter than that.

I don't want people to panic if their golden retriever eats a Hershey's kiss. Many dogs could eat a very small quantity of something like a milk chocolate and experience no symptoms. However, if vomiting or diarrhea, lack of appetite, lasts more than a couple hours, or if the pet is experiencing anything else - hyperactivity, pacing - that is going to warrant a call to a veterinarian.

Are there any new toxins pet owners should be aware of?

Xylitol. It's a sugar substitute, and it's appearing in more and more products. It can be in cookies, breath mints, chewing gum, puddings, baked goods, jams, jellies. The newest place this has popped up is in peanut butter, and a lot of people use peanut butter as a treat or a way to conceal a pill for their dogs.

In people, it's great. However, it's toxic to dogs. It causes increased insulin secretion and causes blood sugar to drop very severely, which can be difficult to treat in a veterinary setting and almost impossible at home. If you can figure out that this happened, if you know right away it was a xylitol-containing product, I wouldn't even wait a few hours. I would be on my way in.

Dr. Drobatz, what's the most common reason you see for a pet coming to the emergency room this time of year?

Vomiting and diarrhea. We see a lot more animals coming in - dogs, in particular - because they've been given foods they shouldn't eat. Some table foods are high in fat, which can cause irritation. Even just changing food, some dogs are sensitive to that.

Also, this is the time of year when pets can get into ornaments. Cats like tinsel because it's like string. It can get caught in the intestine. The intestine keeps trying to move it on, creating a sawing action, and that can result in a hole in the intestine. They can die from it. Don't pull on it. Come see a vet.

Anything a dog could potentially swallow is a risk. Dogs can get those batteries in toys. It's not frequent, but it's something we're concerned about this time of year. Everyone's excited and wrappers are all over the floor and no one's paying attention and the dog gets something. You'd be surprised how big a thing a dog can eat. I've seen puppies that have eaten foot-long rulers and whole spoons.

Another thing with the holidays: We see pets, dogs in particular, that are acting strangely, not mentally appropriate. They are otherwise healthy animals. After some discussion, we find that the kids are home from college. It's marijuana toxicity.

Apparently, dogs get into the most trouble. What about cats?

With a lot of company coming over, cats get stressed out. They hide more. They're a lot more psychological animal than a dog. Maybe put them in a place where they're not exposed to all these people. Put them in a room where they're comfortable and give them familiar bedding.

Overall, what's the best thing you can do to keep your pet safe during the holidays?

More than anything, diligence.