Ranger, a four-year-old German Shepherd, will look like a puppy forever because of a rare condition that impacts his growth.
The dog has pituitary dwarfism, which her owner says was caused by inbreeding, and will only ever grow to around a third of the size of a regular adult German Shepherd.
Despite the fact the condition will cause long-term health issues and lead to a short life expectancy, Ranger's owner Shelby Mayo says she has received requests to breed the dog to create more 'forever puppies'.
The 20-year-old student nurse from Phoenix, Arizona, said the focus should be on preventing conditions like Ranger's.
"Ranger is very cute and he's a great dog, but ultimately this is the result of inbreeding and we want to stop that. Breeders need to be aware that this can occur and they need to try and prevent it," she said.
"Ranger has had a good life so far but that's not the case for all."
Dwarfism is more prevalent in certain breeds of dogs, including German Shepherds and corgis, and can lead to a dog living for just three years.
Both parents of the dog must have the carriers of the gene for a puppy to inherit the genetic condition.
"The lack of growth hormone results in slow growth from about two months of age. Affected puppies are very obviously smaller than their littermates, and also fail to grow an adult coat - their fur remains soft and woolly," vet Lynne Janes told The Daily Star
"In many cases while the coat may recover, the dwarfism is irreversible and these puppies do not grow to their expected adult size.
"Unfortunately, the condition is life-limiting, and many dogs with the condition sadly die before they are three years old.
"Inbreeding can be a factor and dogs who are known to have produced a puppy with dwarfism should not be bred from again."
Ranger initially lost all his fur as a puppy due to low thyroid levels, but he has since been put on medication and managed to grow it back.
He has previously also had difficulties eating, but Mayo says he now has a healthy appetite.
She and her sister Darcy run an Instagram page for Ranger which has grown to 138,000 followers
They use the page to raise awareness of the issues related to inbreeding.
Ranger lives with his big sister Jessie and Mayo says despite his size he still manages to keep up with her and regularly takes her on in play battles.
Ranger and his family sell merchandise and regularly take part in fundraisers for Pets with Disabilities Rescue, a charity that works to rehabilitate and find new homes for pets with disabilities.
Featured Image Credit: ranger_thegshepherd/Instagram