PK-def or more properly Pyruvate Kinase Deficiency is a recessive inherited enzyme deficiency that may cause anaemia in some affected cats.  PK-def is genetic and can’t be passed in any other way than by breeding an affected or carrier animal.  Since it is hard to detect it is fortunate that there is a DNA test performed which can detect the gene.  This DNA test can be easily done by cheek swab or blood test. The test will reveal results as 'normal' like all our cats, 'carrier' or 'affected'. 

• Affected cats posses two PK Def. genes and will have had both parents who are either affected or are carriers - inheriting one faulty gene from each parent.  It would seem that some affected cats do not show any symptoms for many years whilst others develop anaemia that proves fatal. It is unsafe to breed from an affected female as it will most likely kill her and could well also mean an aborted pregnancy too.
• Carrier cats, i.e. those who have inherited only one PK Def. gene, will not develop PK Def. and will therefore not suffer from this type anaemia.  Breeding a carrier with a normal is a recognized way of keeping these bloodlines going.  The offspring will be either PK Def normal or a carrier, so all kittens kept for further breeding purposed should be tested.
• Normal means that the PK Def. gene has not been detected by the test. All kittens from a set of PK Def. Normal parents will be clear from this genetic deficiency and are therefore clear to breed as long as they are otherwise fit, healthy and of good type for the breed.

Remember this is a simple recessive, easily removed from the gene pool through DNA testing and responsible breeding. A cat that has PK deficiency has 2 mutant genes, one from each parent, meaning that both parents were at least carriers.   While some males have lived long, healthy, productive lives only to test as affected at a ripe old age, it is good to take the time to think about the numbers of carrier or affected kittens that male might well have produced before being tested! Females are not so lucky; they tend to have trouble with their first litters: aborting, premature delivery, or death of the female. No known PK Def. affected female should be used for breeding!

Although in order to not lose cats and bloodlines, you can breed a known carrier to a known clear cat. Then test any kitten you consider keeping or selling for breeding purposes.  Only keep a normal kitten, or you will have the same problems when it comes to breeding them!  With Rheumatoid Arthritis (RA) rampant in Abyssinians, it is imperative that we use some of the PK Def. carriers, who come from bloodlines not affected by RA or we’d wind up with too small a gene pool to breed from safely.  Carriers will not become ill with the disease, so when bred to clear cats none of the offspring will become ill as they will be carriers at most.  The basic rule is “If a cat is affected, neuter it!”  If it is VERY important to use a male, breed the affected male to a known normal female and keep one of the kittens. There is no need to test this kitten it IS a carrier. Breed that kitten to known normal cats only, and test any of those that you keep or sell for breeding.

 ©Lovelynx Abyssinians 2007-10