The smell of coffee or chocolate candy can tempt both humans and animals. But unlike humans, pets don’t know the difference between safe and dangerous foods. And when they eat or drink things they shouldn’t, the results can be disastrous.

Many human foods are safe for pets, says Dr. Tina Wismer, medical director at the American Society for the Prevention of Cruelty to Animals’ Animal Poison Control Center. But when an animal gets a bite of something it shouldn’t, it might be a good idea to call the doctor.

When to call for help

If a pet has consumed only a little of a substance and immediately thrown it up, a little TLC at home might be sufficient. But Wismer advises dog and cat owners to follow their gut instincts. If a pet continues to be sick, call the vet.

“Dietary indiscretion can cause stomach upset, diarrhea, anorexia and lethargy,” she says. “If your pet is not acting normal, it is time to call the veterinarian.”

Sometimes, pets get into things without the owner knowing, so it can be more difficult to figure out what’s going on. While an emergency vet visit can be costly, it might be the best way to get a dog or cat on the road to recovery, Wismer says.

“Always call as soon as possible if you suspect your pet has gotten into something they shouldn’t have,” she says.

“If vomiting needs to be induced, we don’t want there to be a delay, but you should never provide treatment to your pet without consulting a veterinarian first. Some toxins could be more harmful coming back up than they were going down.”

Little-known toxins

You might leave some foods out without a second thought, but these can be toxic to your pets:

Beverages. The ASPCA recommends avoiding coffee—or anything with caffeine—and alcohol.

Raw protein. Eggs and raw or undercooked meat of any kind can contain harmful salmonella and E. coli.

Fruit and nuts. Grapes and raisins can cause kidney failure, and avocado can cause vomiting and diarrhea in dogs. Macadamia nuts are also harmful.

Vegetables and herbs. Onion can cause upset stomachs, particularly in cats, according to the ASPCA. Garlic and chives also can lead to gastrointestinal irritation and even red blood cell damage.

Some staples. Milk, bread dough, salt, and xylitol, a sugar substitute, have also made the ASPCA’s list of no-nos for pets.