Genetic Testing, Fluffy and Bluie

There are three main diseases that affect the Corgis- DM, EIC and VWD1.

Degenerative Myelopathy (DM) is a progressive disease of the spinal cord in some older dogs. The disease has an insidious onset typically between the age of 8 and 14 years old.  It begins with a loss of coordination (ataxia) in the hind limbs.  The affected dog will wobble when walking or drag their feet.  This can first occur in one hind limb and then affect the other.  As the disease progresses, the limbs become weak and the dog begins to buckle and has difficulty standing.  The weakness gets progressively worse until the dog is unable to walk.  The clinical course can range from 6 months to 1 year before dogs become paraplegic.  If signs progress for a longer period of time, loss of urinary and fecal incontinence may occur and eventually weakness will develop in the front limbs.  Another key feature of DM is that it is mercifully not a painful disease.

Exercise-Induced Collapse (EIC) is an inherited neuromuscular disorder affecting Pembroke Welsh Corgis. EIC presents as exercise intolerance in apparently healthy dogs. Affected dogs are usually diagnosed before two years of age and appear normal during low to moderately strenuous activity. However, shortly after 5-20 minutes of strenuous exercise affected dogs will begin to walk with a wobbly, uncoordinated gait that often only affects the hind limbs. Dogs remain mentally alert and are not in pain during episodes of EIC. In some circumstances, the symptoms of EIC can progress to full body weakness with low muscle tone (flaccid paralysis), confusion, loss of consciousness, seizures and very rarely, death. The episodes typically last 5-10 minutes and most dogs will completely recover within 15-30 minutes.

Von Willebrand Disease (VWD1) is a genetic disorder that prevents normal blood clotting and can cause extended bleeding following injury or surgery.  The disorder results from a deficiency or lack of sufficient Von Willebrand factor (VWF) which functions as a binding protein during blood clotting.  Three types of VWD have been identified in dogs to date and are known as VWD type 1, 2 and 3. Von Willebrand’s Disease type 1 (VWD1) results in reduction in normal levels of VWF to approximately 5-10% of normal.  Since some VWF is produced in dogs homozygous for the VWD1 mutations, this form of the disorder is considered to be less serious than type 2 and 3.  The mutation (G >A substitution) has variable penetrance and is recessive requiring two copies of the mutation in affected dogs.  Typical symptoms of the disease encompass exessive or abnormal bleeding following injury or the presence of blood in various secretions (urine, feces, etc.)

The tests will provide one of three results for breeders testing their dogs:

CLEAR – dog does NOT HAVE the mutated gene; therefore, cannot pass it on or get the disease.

CARRIER – dog has one copy of the mutated gene and can pass it on but NOT get the disease.

“AT RISK” – dog has two copies of the gene and stands a risk of actually developing the disease as well as passing it on to offspring. 

An At Risk test result, however, does not guarantee the dog WILL develop the disease. Research is continuing, hoping to discover what “triggers” the gene to cause the disease to develop.

All of our corgis are tested for all 3 diseases to ensure none will be bred to produce at risk puppies.

Coat Length- Fluffy 

A “fluffy” is the name of a corgi with a longhaired coat. The specific gene that causes a fluffy coat in corgis is referred to as the “fluff-gene” and it is the result of a recessive genetic coat mutation. Fluffy corgis are not known to suffer from any unique health effects due to this genetic mutation. They simply have longer hair. Aside from a difference in coat length, fluffy corgis and standard corgis are the exact same dog and they can even be born in the same litter. Fluffies do tend to have more demanding grooming requirements than standard corgis and future corgi owners should take that into consideration when deciding whether or not a fluffy corgi is right for them. Some fluffy corgis are found to shed less than standard coat corgis. Unfortunately, fluffy coats are considered to be a fault in a corgi’s conformation and therefore they are not able to be shown. The fluffy coat type only appears in offspring when both parents carry the recessive fluff-gene and pass that gene on. A puppy will need to receive both of its parent’s “fluff genes” in order to be fluffy. If they only receive one of the two, then they will carry the fluffy gene but never develop a fluffy coat. Unless a dog’s coat genes are specifically tested, it is difficult to know whether or not they carry the fluff gene.

Color- Bluie

The “bluie” Pembroke Welsh Corgi can occur in any color (red, sable or tricolor). It is easiest to see in the tricolor, as the areas on the coat that are normally black take on a decided gunmetal blue hue. The red and sable bluies have a smoky cast to the red coloring. The colored portion of the coat has a distinct bluish or smokey cast. This coloring is associated with extremely light or blue eyes and liver or gray eye rims, nose and lip pigment. The bluie color only appears in offspring when both parents carry the recessive D- locus gene and pass that gene on. A puppy will need to receive both of its parent’s “bluie genes” in order to be a bluie. If they only receive one of the two, then they will carry the bluie gene but not have the bluie coloration. Unless a dog’s genes are specifically tested, it is difficult to know whether or not they carry the bluie gene.