This means that the affected animal must have two mutant PK genes to show clinical signs of the disease. Animals classified as carriers have one mutant gene and one normal PK gene and are clinically asymptomatic. These animals, however, can pass the mutant gene to their offspring. PK deficient dogs and cats experience anemia, but the clinical signs are different. Affected dogs experience exercise intolerance, lethargy, severe chronic anemia, spleenomegaly and osteosclerosis.
Affected dogs die because of anemia and hepatic failure and death by five years of age.
Clinical signs of anemia in affected cats are intermittent with episodes of pallor and lethargy. They do not develop osteosclerosis and may have a normal life expectancy. The oldest clinically diagnosed cat with PK deficiency was 14 years of age. Genetic tests have been developed or established at the University of Pennsylvania to accurately diagnose PK deficiency in Basenji, West Highland White and Cairn Terriers, Abyssinians and Somali cats, in order to detect the presence or absence of the mutant gene. These tests, therefore, can assist breeders and pet owners with important health and mating decisions.