Adult German Shepherd will never outgrow puppy body due to rare condition

At first glance, Ranger looks like any normal German Shepherd puppy, with his big ears and coloring that is distinctive to the breed.

But fans of the Instagram-famous pup will be shocked to know that despite his puppy face, Ranger isn't really a puppy at all — he's actually 2 years old.

The dog, who lives in Phoenix, Ariz., with his owner, Shelby Mayo, and his siblings, Hazel the Labrador and Jessie the German Shepherd, has a genetic condition that will make it look like he's a puppy for his entire life.

"When we originally got Ranger from the breeder, he was smaller than all his other littermates, but we figured that was because he had a parasite called Coccidia," said Mayo, according to The Daily Mail. Doctors noticed he had Giardia, a parasite, as well as infection on his neck, and that he wasn't really growing.

"During this time Ranger remained very small, the vet had suspected that he may have Pituitary Dwarfism, a genetic mutation," Ranger's owner continued. "But we were still skeptical as this condition is very rare. Over time Ranger still did not get much bigger, and at this point, we are certain he does have this condition."

After he was neutered, Ranger started developing many medical issues that are common for dogs with Pituitary Dwarfism, including a loss of appetite and weight, flaky skin and a loss of hair.

"After getting Ranger on Levothyroxine and using this soap, his fur grew back and the dryness went away," said Mayo, who regularly documents her dog's escapades to their nearly 68,000 followers on Instagram.

"He [is] healthy and happy as can be as of now and loves jumping around and playing with his ball and squeaky toys with his two sisters, Hazel and Jessie."