With their super short legs, low-set bodies, and outgoing, lively, and independent temperaments, corgis and dachshunds are dog breeds that are beloved all over the world. Being short is just part of what makes these dogs who they are, and their little waddle walk is simply another reason why people love them. But have you ever wondered why corgis and dachshunds are so short? Well, wonder no more, because this article will fill you in on the long and short of it.
Meet FGF4, a Growth-Stunting Gene
Corgis and dachshunds have a type of dwarfism called chondrodysplasia (also known as achondroplasia) to thank for their short legs. Chondrodysplasia is a hereditary condition in which the cartilage develops at an abnormal rate. Chondrodystrophic dogs have that instantly recognizable long-body short-leg look.
Recent scientific studies have identified a gene called FGF4 (or fibroblast growth factor 4) that causes short legs in specific breeds. Without getting too scientific, this gene was duplicated and inserted into a different place in the dog genome over time. This extra copy of the gene (which is known as a retrogene) stunts the growth of the dog.
In a nutshell, scientists believe that having two copies of this gene causes dogs to overproduce the FGF4 protein, which activates another protein called FGFR3, which in turn, leads to dwarfism. Interestingly, in humans, overactive FGFR3 is responsible for the most common type of human dwarfism, called achondroplasia.
Once it was discovered that shorter legs meant it was easier for dogs to herd domestic animals (they’re the perfect height for ankle nipping, you see) and even easier to flush burrowing animals out of their hide holes, owners caught on. What started as a genetic malformation in some breeds turned into a classic case of selective breeding.
Does Having Short Legs Impact Corgis and Dachshunds?
Having such short legs is part of what makes corgis and dachshunds the beloved breeds they are today. These days, their shortness is no longer beneficial for tasks like herding or hunting, and other than increased agility (and increased cuteness!) being short doesn’t have any specific advantages.
Rather, having such short legs comes with a handful of disadvantages. Firstly, if you daydream about running with your dog, here’s a reality check: a dwarf breed is not the right option for you. This is because high-impact activity like running and jumping is a no-no for corgis and dachshunds due to the pressure placed on their joints.
Secondly, dogs with shorter legs have a greater risk of developing back problems. Specifically, corgis and dachshunds are predisposed to a condition called Intervertebral Disc Disease or IVDD. This disease is a neurological condition that is caused by a herniated disc and compression of the spinal cord. Its symptoms are pain, anxiety, limping or lameness, incontinence, and paralysis.
Finally, dogs with chondrodysplasia are also more likely to develop a host of common health issues. Such dogs are at higher risk of developing dog arthritis, are prone to obesity, and may experience trouble breathing down the line.
Which Other Breeds Have Dwarfism Genes?
Dachshunds and corgis might be the two most well-known dogs with dwarfism, but in reality, many other breeds havechondrodysplasia. There are thought to be around 19 different dwarf dog breeds. Get ready! Here they are:
- Alpine Dachsbracke
- Basset hounds
- Boston Terriers
- Cardigan Welsh Corgis
- Dandie Dinmont Terriers
- English bulldogs
- French bulldogs
- Miniature Schnauzers
- Pembroke Welsh Corgis
- Schweizerischer Niederlaufhunds
- Scottish Terriers
- Shih Tzus
- Skye Terriers
- Tibetan Spaniels
- Welsh Corgis
The breeds mentioned above are all known for their curved legs and short stature, but also for their typically sassy temperament. What they lack in height, they sure do make up for in personality.
If you adopt a dog with dwarfism, you should know they’re generally great for families with kids. You can make their lives just a little bit easier by purchasing dog-friendly home décor, like steps that lead to the couch or elevated food bowls. You may also feed them a balance diet to prevent obesity and back problems.
The Difference Between Chondrodysplasia and Pituitary Dwarfism?
Just like there are more than 400 types of dwarfism in humans, there are many different kinds of dwarfism in dogs. The two most well-known forms of dog dwarfism are chondrodysplasia and pituitary dwarfism. What separates the two different types of dwarfism?
As you know by now, chondrodysplasia is a hereditary disorder in which the cartilage develops at an abnormal rate. Pituitary dwarfism, which is also known as juvenile-onset panhypopituitarism, is a growth deficiency that is usually caused by a lack of growth hormone produced by the pituitary gland. This type of dwarfism is also known to be proportional, so all parts of the dog are smaller as opposed to just the legs.
Chondrodysplasia is the most common type of dwarfism in dogs while pituitary dwarfism is rarer. The breeds mentioned earlier are chondrodystrophic breeds, and having short legs has long been officially recognized as part of their breed standard. Meanwhile, dogs with pituitary dwarfism are individual dogs that are significantly smaller than the average size dog of that breed.
What Breeds Are Prone to Pituitary Dwarfism?
There is no real reason to explain why, but some breeds are more likely to develop pituitary dwarfism than others. These breeds have been identified as:
And finally, one of the biggest differences between chondrodysplasia and pituitary dwarfism is the life of the dog. Chondrodystrophic breeds have normal lifespans for their size, but those with pituitary dwarfism have shortened lifespans. Dogs with chondrodysplasia, like corgis and dachshunds, have lifespans of around 12 to 15 years. Sadly, dogs with pituitary dwarfism rarely live to see their fourth birthday.