Dwarfism in dogs is usually the result of a deficiency of GH, or a growth hormone, but what is not well known to most owners, is that there are other potential causes.
Each potential cause will show several different symptoms and some of these causes can have much more serious implications than just dwarfism.
Perhaps the best known cause of Dwarfism is from a condition referred to as hypopituitarism.
This condition will develop in young dogs and is a result of a deficiency of GH, which is the growth hormone that is normally secreted from your dog’s pituitary gland.
When hypopituitarism is present, one or more of these pituitary hormones are not produced in normal amounts, and as a result, it causes dwarfism.
This condition is almost always associated with primarily two breeds; German Shepherds and Carnelian bear dogs. However, it can also affect Sptiz, Toy pinchers, as well as Weimaraners.
If this condition is inherited, it is believed by the medical community to be a simple autosomal recessive trait.
This is best described as a situation where the puppy receives only one defective gene, but from both of their parents.
If a puppy receives only one defective gene, they will automatically become a carrier, but usually do not show any signs of dwarfism.
However, Dwarfism in dogs may also be the result of the pituitary glands not developing properly which cause abnormalities to occur.
If puppy’s pituitary glands do not develop normally, or if a cyst occurs, the hormone production may be decreased, or is some cases, totally absent.
This can also occur if the pituitary glands are affected by benign tumors.
When any of these conditions do occur, a puppy will appear to be totally normal at birth, but they will begin to show the signs of dwarfism by the age of two to three months.
Dogs that are affected with dwarfism caused by pituitary problems will have normal proportional sizes to their limbs as well as their trunk and other body structures.
However, they are simply much smaller than they should be.
With this form of dwarfism in dogs there are several symptoms that you can watch for as it starts to develop. The first symptom is the most obvious one; they will be much shorter in stature than their litter-mates.
There is often a misconception that the entire litter will be small, but in almost every case it will be just one or two dogs in the litter that are affected.
The next symptom to watch for is the retention of their puppy coat, and as a result, their hair will be very soft and woolly.
Because of this, they will quite often over a period of time, develop alopecia, which is also known as hair loss.
The next set of symptoms will be hyper-pigmentation, or darkening of their skin.
The teeth are also affected, as there is usually a delayed eruption or an absence of permanent teeth altogether.
If it is a male dog, their testicles will also be very small, and in some cases they will be infertile. If female, estrus or heat may be totally absent, and they also may develop infertility.
There is also one very common symptom with this cause of dwarfism; your dog will develop a very shrill bark.
The next potential cause of Dwarfism in dogs is from OCD, also known as Osteochondrodysplasia, as well as Achondroplasia.
OCD is a situation where the growth and development of the bone and cartilage in your dog is abnormal.
Because of this, there is a lack of normal bone growth and bone formation.
The breeds that are most affected by this condition include Alaskan malamutes, Samoyed's, Scottish deer hounds, and Labrador retrievers.
However, Pyrenees, Basset hounds, and Norwegian elk hounds are also affected.
Achondroplasia is a form of OCD, but it is a situation where the bones do not grow to their normal size for that particular breed.
When these situations occur, their limbs are abnormally short, making it actually more of a true case of dwarfism than a pituitary cause.
It is thought to be caused by a mutation of the fibroblast growth factor reception gene.
There are some breeds where this trait actually selectively encouraged; most notably Dachshunds. Skye terriers and Welsh corgi also fall into this grouping.
Both of these disorders are considered to be genetically acquired, but OCD may be slightly different.
It is considered to be an autosomal dominant genetic disorder, which means that it can be passed by either parent, but only one parent needs to carry the gene.
The symptoms or signs that you will see with this form of Dwarfism in dogs is a slightly larger than normal head, as well as an undershot jaw with a shorter nose.
Because of the shorter jaw, the teeth may be crooked in some dogs.
They will also have an abnormal bone shape as well as enlarged joints.
They may also have what would be considered bull legs in humans, where there is a sideways bowing of the forelimbs. This usually affects the front legs much more than the back legs.
Dwarfism in dogs may also be caused by a metabolic disorder that is the result of impaired functions of your dog’s lysosomal enzymes.
These enzymes help in building your dog’s bones, cartilage, skin, and tendons.
They also assist in creating the fluid that is responsible for lubricating their joints.
The breeds that are affected by the metabolic disorders that result from this condition include Plott hounds, Labrador retrievers, as well as German shepherds.
Also affected are Miniature pinchers and Schnauzers, as well as mixed breeds.
Dwarfism with this condition is the main symptom. However, unlike the other possible causes, it is much more dangerous to your dog.
It can also cause severe bone disease, DJD including dislocation of the hip, as well as facial deformity. It can also cause your dog to have an enlarged liver as well as an enlarged tongue.
Dwarfism in dogs in the vast majority of cases is not a serious health threat to your dog, unless it is the result of a metabolic disorder.
Just because a dog is considered a dwarf, their heart and love for you will be just as large as if they were considered normal size.