The genes of your Welsh corgi—whether Pembroke or Cardigan—all but ensure an affectionate, loyal pooch of short stature. But your dog's genes also convey a higher risk for certain congenital diseases. In many cases, early intervention can help you keep your low rider in top form.
Canine Degenerative Myelopathy
In 1941, baseball great Lou Gherig lost his fight with amyotrophic lateral sclerosis, or ALS. Nearly half a century later, Dr. Gary Johnson and his colleagues found that degenerative myelopathy, a neurologic disease common in Pembroke Welsh corgis, may be caused by a mutation of the gene associated with ALS in humans. Degenerative myelopathy generally affects corgis 8 years and older. It begins with instability or weakness in the rear legs and within three years progresses to paralysis of the hindquarters. While degenerative myelopathy cannot be cured, rehabilitation, acupuncture and dietary supplements may be helpful. A DNA test is now available and strongly recommended for both Pembroke and Cardigan Welsh corgis. And with the discovery of Johnson's team, it appears corgis could help scientists find a cure for both species.
Severe Combined Immunodeficiency
First described in children in the 1960s, severe combined immunodeficiency—or SCID—is an inherited disorder that affects humans, mice, horses and dogs. SCID has been identified in only three dog breeds: Jack Russell terrier, basset hound and Cardigan Welsh corgi. Affected dogs fail to produce an effective immune response to bacterial, fungal and parasitic infections. Recurrent respiratory, skin and ear infections often accompany diarrhea in puppies, starting at 6 to 8 weeks of age. Few survive past 3 to 4 months of age. SCID is an X-linked recessive trait, meaning only males are affected, but females can carry the trait and pass it on to their offspring. A test has been developed that can identify not only affected animals, but clinically healthy carriers of the mutation.
Progressive Retinal Atrophy
Progressive retinal atrophy, a degenerative disease of the retina, was first recorded in Cardigan Welsh corgis in 1972. Recently, a surge of cases has been documented in the Netherlands, New Zealand and the United States, with affected dogs all sharing ancestry traced back to common stock in the United Kingdom. In affected corgis, the nerve cells and blood vessels of the retina degenerate, leading to blindness in young adult dogs. Early symptoms often include a loss of night vision, as the disease first attacks the retina's light sensitive rod cells. Other symptoms may include dilated pupils, highly reflective retinas, and peripheral vision loss. While there is no treatment for progressive retinal atrophy, dogs tend to adapt well to blindness. Genetic tests can confirm the disorder, as well as identify those carrying the mutation.
Pembroke Welsh corgis are at an increased risk for blood shunting or blood clotting disorders. Patent ductus arteriosus occurs when a short blood vessel duct or "shunt," used to circumvent blood from a developing puppy's lungs, fails to close after birth. Affected puppies often are smaller than their littermates and less playful. Symptoms of a shunt may include shortness of breath, coughing, decreased stamina, weight loss and difficulty breathing. Depending on the severity, dogs often require surgery to correct the shunt. Pembroke Welsh corgis can also inherit Type 1 von Willebrand disease, a mild blood clotting disorder caused by a lack of von Willebrand factor, necessary for proper platelet function. While von Willebrand disease can not be cured, it can be managed. An accurate genetic test has been developed for Pembroke Welsh corgis; it should be administered if a clotting disorder is suspected.
Always consult an experienced veterinarian regarding the health and treatment of your pet. Affected animals or those identified as carriers of a genetic disease should never be used for breeding.
- Proceedings of the National Academy of Sciences: Genome-Wide Association Analysis Reveals a SOD1 Mutation in Canine Degenerative Myelopathy that Resembles Amyotrophic Lateral Sclerosis
- Veterinary Pathology: Molecular Pathology of Severe Combined Immunodeficiency in Mice, Horses, and Dogs
- Veterinary Pathology: A von Willebrand's Factor Genomic Nucleotide Variant and Polymerase Chain Reaction Diagnostic Test Associated with Inheritable Type-2 von Willebrand's Disease in a Line of German Shorthaired Pointer Dogs
- University of Cambridge: Inherited Diseases in Dogs
- University of Prince Edward Island: Canine Inherited Disorders Database
- The University of Sydyney: List of Inherited Disorders in Animals
- Orthopedic Foundation for Animals: DNA Testing for Degenerative Myelopathy
- LABOKLIN: X-SCID
- VetGen: Von Willebrand's Disease
Barbara Cozzens has been writing for more than 20 years. Her work has appeared in publications of the Nature Conservancy, the World Bank Group, National Geographic Society, Duke University and others. Cozzens holds a Bachelor of Arts in biology from Colgate University and a Master of Environmental Management from Duke University's Nicholas School of the Environment.