Hedgehog Balloon Syndrome Sounds Adorable, Can Be Deadly

A European hedgehog (Erinaceus europaeus) munches grass in the Scottish countryside Nature Picture Library/Getty Images

It may sound adorable, but a hedgehog puffed up like a balloon is actually in pain. This puzzling condition, which causes a hedgehog to inflate from the relative size of a softball to that of a basketball, is fittingly known as balloon syndrome.

Balloon syndrome is a rare hedgehog affliction in which an injury or infection causes an abundance of gas to become trapped under the skin, causing it to inflate around the hedgehog's body. Sometimes the condition is less noticeable, with just some puffiness atop the little creature's spine. Other times, it's remarkable.


Such was the case with Zepplin, named for zeppelins, the gas-filled dirigibles of the early 20th century. The injured wild hedgehog was discovered on July 23, 2017, along the side of a rural Scottish road. A passerby rushed the swollen animal to the Scottish Society for the Prevention of Cruelty to Animals, where experts could only guess at the cause of his seriously inflated condition.

Whether Zepplin was hit by a car, causing blunt trauma, or injured by a scuffle with another animal will remain a mystery, but he didn't appear to have an infection — the other possible cause of balloon syndrome, veterinarians said. Whatever the cause of the injury, Zepplin's glottis, a valve at the top of his windpipe, was involved in what happened.

The air Zepplin inhaled would normally have gone out of the hedgehog's lungs, past the glottis and out of his nose and mouth. Instead, due to a malfunctioning glottis, the air forced its way out Zepplin's lungs through minute tears in the lungs and rib muscles. As the injured hedgehog continued to breathe, more air made its way its body. And, because hedgehogs don't have much connective tissue adhering their skin to underlying muscle, as the inflation continued over approximately 48 hours, Zepplin achieved beach ball proportions.

To deflate Zepplin, surgeons made four incisions in his skin to slowly release the air and return him to normal size. Without medical intervention, Zepplin would most likely have died in the wild because he'd be unable to protect himself from predators. However, after he was deflated, and once again able to curl up into a defensive mode, veterinarians released him to wander the Scottish countryside.

Zepplin's not even the first hedgehog to cause a social media stir with balloon syndrome this year. Monty the hedgehog — named for the hot-air-balloon pioneering duo of French brothers Joseph-Michel and Jacques-Étienne Montgolfier — puffed up back in June, but was released safely into the wild on August 7, 2017 after treatment and recovery.

sonic the hedgehog balloon macy's day parade
The Macy's Day Parade Sonic the Hedgehog balloon has nothing to do with the affliction some real-life hedgehogs experience. But hey, we couldn't resist.
Andrew Toth/Getty Images for Sega of America