Dubbed Monty by rescuers, the animal had inflated to twice his natural size but is now back in its natural habitat after spending several weeks in the care of the RSPCA.
The hedgehog was suffering from a rare condition called subcutaneous emphysema, which is more commonly known as ‘Balloon Syndrome’.
The condition - where air collects under the skin causing the animal to inflate like a balloon - is caused by a traumatic event, like an injury, or underlying infection.
RSPCA inspector Sandra Dransfield, who collected him after a call from a concerned member of the public on 5 June, said: “This hedgehog has been through a lot.
“The condition he was suffering from would have been fatal if he hadn’t been spotted. We really did get to him in the nick of time.
“I’m so happy that he’s pulled through and is now back where he belongs.”
He was noticed by a member of the public going round in circles in the Toll Bar area of Doncaster. When she called us, she described him as dragging his back leg and having blood on his nose and, due to his size, thought he might be pregnant.
“When I arrived I knew what it was,” said Insp Dransfield. “He was a big male - nearly 1kg - but was so inflated he was almost twice his natural size. He couldn’t get all four feet on the ground at the same time, so clearly couldn’t move or feed properly.
“What happens is the air fills up the space that allows them to roll into a ball, which is how hedgehogs protect themselves from predators when they’re sleeping or feel threatened, so he was very vulnerable. He couldn’t even tuck his head in.
“It was the worst case of Balloon Syndrome I’ve ever seen.”
He was taken straight to Peak Vets in Sheffield, where he was x-rayed and they released some of the air from under his skin. They put him on antibiotics and pain relief then he was transported to the RSPCA’s closest wildlife centre - RSPCA Stapeley Grange in Nantwich, Cheshire - where he’s been been cared for ever since.
Staff nicknamed him ‘Monty’, after the Montgolfier brothers who invented the hot air balloon.
Monty was put under general anaesthetic to have the rest of the air released and after several weeks of TLC has now happily been released back to the area where he was collected from.
Lee Stewart, manager at RSPCA Stapeley Grange, said: “It is rare that we get hedgehogs with Balloon Syndrome, particularly this severe.
“It’s always great when we’re able to successfully rehabilitate an animal and release them back into the wild, that’s the whole point of the work we do here.”
If you see an animal you have concerns about please call the RSPCA's emergency line on 0300 123 9999.