Pyruvate Kinase Deficiency (PKD)

Description

Pyruvate Kinase Deficiency (PKD) is an autosomal recessive disorder that affects red blood cells. Autosomal recessive disorders are disorders that can be passed from either parent and require two copies of the gene to show symptoms. Dogs suffering from Pyruvate Kinase Deficiency have a mutated form of pyruvate kinase, an important enzyme in cellular metabolisms.

This defect causes the red blood cells to die, leading to severe hemolytic anemia. Hemolytic anemia is the abnormal breakdown of red blood cells. Because red blood cells deliver oxygen to tissues around the body, it is important that dogs are able to maintain an adequate supply of red blood cells. Dogs suffering from PKD deficiency typically are chronically anemic (having low Oxygen).

Symptoms of PKD usually begin to show between four months to one year of age. The symptoms include:

• weakness
• lack of energy
• rapid heart rate
• heart murmurs
• pale gums
• stunted growth

As the disease progresses, bones and the liver can be affected. The disease is ultimately fatal. Dogs with PKD commonly die before 4 years of age. However, longevity is affected by the breed of dog, with some breeds able to survive longer than others. While there is currently no cure for PKD, it is possible for affected dogs to have a reasonable quality of life with care that focuses on relieving symptoms.

Canine PKD was originally documented in Basenjis; it has since been reported in other breeds, including Dachshunds, Labrador Retrievers, Pugs, Beagles, Cairn Terrier, and West Highland White Terriers.

Because PKD is a recessive disorder, a dog must have two copies of the mutation in order for the disease to manifest. This means that a dog can have one copy of the mutation and not experience any signs or symptoms of PKD. This dog would be known as a carrier. The carrier can then pass on either the normal gene or the mutated gene to any offspring. If two carriers are bred, there is a 25% per puppy that they will develop symptoms of PKD.