Toddlers suffering from kidney failure. One-year-olds undergoing dialysis and transfusions. Parents burying a child. What is the common thread in all these tragedies? Petting zoos. Yes, petting zoos.

As the parents of Colton Guay would surely now attest, no one should underestimate the risks associated with petting zoos. Colton died earlier this month after falling ill with hemolytic uremic syndrome just days after visiting a petting zoo at a Maine fair. Shockingly, 21-month-old Colton wasn’t the first child to die after visiting one of these ubiquitous displays, and hundreds of others have suffered serious—sometimes life-changing—illnesses. Many have battled catastrophic kidney failure, including a 4-year-old who required a transplant.

Getting sick with E. coli is not like eating something that disagrees with you. Symptoms can include bloody diarrhea, abdominal cramping, vomiting and fever, and in severe cases like Colton’s, it can even be fatal.

Children and adults alike have contracted E. coli after petting animals or simply touching the surroundings near a display. The bacteria have been found on railings, bleachers and even sawdust. Toddlers who get the germs on their fingers can transfer them onto their sippy cups or pacifiers or simply suck their thumbs. You can’t tell simply by looking whether an animal is “shedding” E. coli. And pathogens can remain in the environment for extended periods of time.

Getting children to wash their hands thoroughly or keep their fingers out of their mouths is something that few parents have succeeded at. And hand sanitizer does nothing to prevent the spread of E. coli via inhalation. Even vigilant parents can’t fight what they can’t see. A 2-year-old North Carolina boy died of an E. coli infection that he caught at a petting zoo, even though he was under his parents’ direct supervision the whole time.

Outbreaks are neither rare nor isolated, and hand-washing guidelines appear to be making little difference. Kids are still getting sick. After outbreaks in North Carolina, an editorial in the News & Observer concluded that petting zoos “have caused too much pain and sorrow for too many youngsters and their families in this state. Unless and until there’s a completely reliable method of assuring that no young child will contract E. coli-related illnesses at fairs’ petting zoos, the operations, popular as they are, should be prohibited.”

The potential consequences of getting such an infection are so serious that the Centers for Disease Control and Prevention recommends that parents refrain from taking strollers, bottles, pacifiers, sippy cups or toys into animal areas. The agency also advises that children younger than 5 years old should avoid contact with animals in petting zoos altogether.

And let’s not forget the other victims of petting zoos: the animals who are hauled around and forced to interact with crowds of people all day long. Focused on running the display (and making money), operators can neglect even the most basic needs of the animals in their care, including food, water and rest.

There are plenty of ways to enjoy your local county fair or farmers’ market without putting your child’s health at risk or supporting cruelty to animals. Simply stay away from petting zoos, pony rides, animal photo ops or any other type of display that uses animals as props.