Pyruvate Kinase Deficiency (Discovered in the West Highland White Terrier)

Pyruvate kinase (PK) is an enzyme needed for normal energy production by the red blood cells. PK deficiency affects the life span of erythrocytes (red blood cells) that break down particularly easily, which results in hemolytic anemia. Clinical signs include reduced exercise tolerance, weakness, pale mucous membranes, slowed growth, and a heart murmur. Accumulation of iron released from red blood cells damages the liver and bone marrow, resulting in liver failure and abnormal bone density. The disease leads to the death of the affected dog, usually at less than 5 years of age.

Therapy is limited to symptomatic treatments and general supportive care. There is no cure.

There are many responsibilities to consider when breeding dogs. Regardless of test results it is important that your dog is in good general health and that you are in a position to care for the puppies if new responsible owners are not found. For first time or novice breeders, advice can be found at most kennel club websites.

This disease is autosomal recessive meaning that two copies of the mutation are needed for disease signs to occur. A carrier dog with one copy of the PKD mutation can be safely bred with a clear dog with no copies of the PKD mutation. About half of the puppies will have one copy (carriers) and half will have no copies of the PKD mutation. Puppies in a litter which is expected to contain carriers should be tested prior to breeding. Carrier to carrier matings are not advised as the resulting litter may contain affected puppies. Please note: It is possible that disease signs similar to the ones caused by the PKD mutation could develop due to a different genetic or clinical cause.