Quasimodo has a short spine, but a growing following.

The purebred German shepherd has an extraordinarily rare deformity that leaves him with undersized hindquarters, accentuating his burly neck and shoulders and giving the impression of a hunched back.

Since his arrival at Secondhand Hounds in Eden Prairie last month, 4-year-old Quasi is becoming a Facebook favorite and a media darling.

The dog's caretakers established a Facebook page — Quasi the Great — that attracted nearly 70,000 likes in its first week, and he's been featured by major media outlets such as CNN and Esquire.

Quasimodo is one of only 14 dogs in the world diagnosed with short spine syndrome, a condition in which the spine is compressed and shortened, according to a Facebook post. His back slopes down and his tail is a stump. The condition can't be fixed with surgery.

Though it renders Quasimodo unable to move his neck and gives him a distinctive gait, it doesn't cause any pain. "Quasi is able to walk and run, just like other dogs, he just does it in his own way," a recent post on his Facebook page said.

A video on his page shows him playing with his foster family, who are looking after him as he recuperates from surgery earlier in the week.

Found as a stray and taken into a shelter in Kentucky, the rescue workers there thought his growth had been stunted by being confined in a cramped kennel, until they discovered his unusual medical condition, according to his Facebook page. Like two other dogs with this condition, Quasi was named after the protagonist in the novel "The Hunchback of Notre Dame."

A human geneticist is working with Secondhand Hounds to use Quasi's DNA to attempt to find the cause of his condition.

While it's hoped that Quasi will eventually be given a permanent home, he will stay with a foster family until he is deemed healthy, according to a Facebook post.

Among other animals cared for by Secondhand Hounds, a nonprofit animal rescue organization, are Roo Roo, a terrier mix missing two legs, and Traveler, a paralyzed pit bull puppy.

The facility has nearly 200 dogs available for adoption, as well as cats and a rabbit named Echo.

Ben Farniok is a University of Minnesota student on assignment for the Star Tribune.