In top form, Trevor is a dashing black-and-brown dachshund with a long, slender body, stout little legs and droopy ears.

So when his owners found him blown up like a balloon to three times his normal size, they were understandably alarmed.

"When we picked him up, he felt full of air — because he was full of air — but he crackled like bubblewrap underneath your fingers," Francine Jennings, from Cheshire in the United Kingdom, told BBC News.

The 4-year-old dog had somehow sustained an injury to his windpipe that was allowing air to leak into his body and seep underneath his skin, causing him to bloat, according to a statement Friday from the Willows Veterinary Group.

Although it is unclear when it occurred, vets at the Beech House animal hospital in Warrington stitched up the hole, and the dog "deflated," according to the statement.

Jennings, who runs a pet hotel, said she took Trevor to a 24-hour emergency animal hospital because she was concerned about the extreme bloating and because he was struggling to breathe.

Screen Shot 2018 06 02 at 8.01.46 pmTrevor suffering from subcutaneous emphysema. (Ceidiog via Willows Veterinary Group)

"Basically, we came down one day and found Trevor in a bad state," she said in the statement from the veterinary group.

"He literally looked like he'd blown up like a balloon and we had no idea what had happened. He was three times the size he should've been. We put him straight in the car and took him to the 24-hour emergency vets and they had never seen anything quite like it."

Jennings's daughter, Jessica, said Trevor looked like "a big fat seal."

"His whole body was like a blob, and you couldn't tell his face from his neck," she said. "It was horrible seeing him like that. We had to deflate the air out of him — it was weird."

Michelle Coward, a veterinarian who helped treat a swollen Trevor, said she had never seen such a thing, either.

Imaging tests showed Trevor's skin appearing to float away from his tiny body.

He was diagnosed with subcutaneous emphysema — a rare condition in which air gets trapped under the skin's lowest layer called the subcutis or hypodermis. It can occur after a surgery or a traumatic injury. In Trevor's case, veterinarians were puzzled as to a cause.

"Trevor was presented to us with signs of severe air ingress under the skin," Coward said.

"There were no external injuries that would explain how air had got under the skin, so we suspected that an internal injury to the airway or esophagus could have been allowing the air to leak into the body.

"Every time he took a breath, some of the inhaled air escaped through a hole in his windpipe around the muscles and fatty tissue under the skin, and X-rays showed the emphysema was worsening.

"Surgery was the only way to repair the injury but due to its location, there was a significant risk of complications. I have never seen a case like this before, and it was a new surgery for me."

Daschund2(Ceidiog via Willows Veterinary Group)

Trevor underwent surgery to repair the hole in his windpipe — and soon began to snap back to his normal size.

"When he came back for his checkups following the surgery he was very bouncy and happy," Coward, the veterinarian, said in the statement. "He's a great character, and everybody loves him. He was a pleasure to nurse."

Coward said the pooch is not expected to experience any long-term problems from the most-unusual episode.

Trevor's owners said the dachshund, whom they call "Tricky Trevor," has returned to his tiny — and cheeky — self, chasing chickens around the family's property.

Jessica Jennings said, "we wouldn't have him any other way."

Daschund3(Ceidiog via Willows Veterinary Group)

2018 © The Washington Post

This article was originally published by The Washington Post.