Pyruvate Kinase Deficiency, also known as erythrocyte pyruvate kinase deficiency, is a syndrome of hemolytic anemia.  Pyruvate Kinase (PK) is a regulatory enzyme found within red blood cells.  Red blood cells (erythrocytes) that are deficient in the PK enzyme rupture prematurely.  This premature cell rupture leads to hemolytic (red cell rupture) anemia.
     Indications of anemia include; very pale mucous membranes (gums, eye lids, etc.), increased heart rate and pounding pulses, generalized weakness and an intolerance to exercise or activity.  The liver and spleen of anemic dogs may be enlarged.  In dogs over one year of age, the density of the bones appears, radiographically, increased.  If the dog has a relatively inactive life, it may not exhibit any obvious indications of a problem.
     Most often this condition is detected, through clinical indications, in dogs between the ages of four months and one year, although this condition can remain undetected until later in life.
     Most cases of pyruvate kinase deficiency die between the ages of one to four years, due to progressive anemia or liver failure.
     This disorder is hereditary, and is passed genetically as an autosomal recessive gene.  Therefore, this disorder has to be inherited from both parents in order to appear in an offspring.