All Sam Kanizay did was cool his feet off in the water at Dendy Beach in Melbourne, Australia. By the time he'd hobbled home it was a bloodbath.

"By the time I had walked across the sand, about 20 metres, to put my thongs on, I looked down and noticed that I had blood all over my ankles," said the 16-year-old.

Thousands of tiny bites were found all over Sam's feet, baffling doctors and nurses at first. But the problem has now been traced to thousands of tiny flesh-eating parasites, normally attracted to decaying meat.

Sam's ordeal has been put down to bad luck. Experts say he may have disturbed a group of the bugs feeding on a dead fish.

Fortunately, he's now in recovery mode, and has a word of advice for people at his local beach.

"Maybe don't go icing your feet there anytime soon," he said.