Zhang, of Tunkou, bought what he thought was an all-white Pomeranian dog for £60 a year ago on a business trip.
But he found the dog hard to tame, it would often bite him and had several unusual traits, he told the Wuhan Evening Post.
"It can't bark but instead makes little 'em em' noises, and its tail has been growing longer and longer," he said.
"The most annoying thing is that starting this summer, the dog became very smelly. Even when we gave it a daily shampoo bath, the smell was still strong."
Zhang took his 'dog' to a local zoo for answers, and it turned out the dog is actually an Arctic fox, a protected rare species.
He has now donated the animal to the zoo.