Would you reach for Fluffy or Fido’s medicine to treat your illness? Well, you might not ever think of using your pets’ meds, but recent findings published in the journal Antimicrobial Agents and Chemotherapy found that “far too many” adults swipe medicines from their four-legged friends to help treat their own infections, CNN reports.

For the study, researchers didn’t even ask participants about pet meds in their survey about unprescribed antibiotic use. Nonetheless, 4 percent of respondents revealed in the survey that they used antibiotics prescribed for their pets when they wanted to get them without a prescription.

Overall, out of 400 adults from different demographics that researchers surveyed for the study, 14.2 percent said they stored antibiotics at home in case of emergency. Indeed, the major source of these rogue antibiotics wasn’t pet meds; 20 percent of respondents admitted they got their drugs from friends or family; 12 percent said they saved the meds from the last time they were sick; and 24 percent reported they bought the medicine abroad.

But the number of people who confessed they filched veterinary meds prescribed for their pets surprised researchers. “We metabolize things differently than animals do, and these drugs are formulated for animals,” warned Barbara Trautner, MD, PhD, director of clinical research at Baylor College of Medicine in Houston and co-author of the study.

Trautner added that if a patient were ever to ask her about taking their pet’s medication, she would liken it to how chocolate can be poisonous for dogs but is fine for humans. Her point is that it may be dangerous for humans to take antibiotics designed for an animal’s immune system.

What’s more, taking animal antibiotics or using the bacteria-fighting drugs without a prescription can also be a big threat to human health. Previous studies show that communities of people who take these drugs without a doctor’s supervision tend to have more problems with antibiotic resistance. In addition, the world is already experiencing an uptick in the number of so-called superbugs that today’s antibiotics cannot combat. Study authors warned that people popping pet meds might be making things even worse.

To learn more about the dangerous effects of antibiotic resistance, click here.