Pyruvate kinase (PK) is an enzyme in the red blood cells that is needed for the production of energy within the cell.

When there is a deficiency of this enzyme, the red blood cells cannot produce the energy they need to survive, and an affected cat will be prone to anaemia (a lack of red blood cells in the blood).

Red blood cells are the oxygen carrying cells in the blood.

Pyruvate kinase (PK) deficiency is a recessively inherited disease, seen in Abyssinian and Somali cats, as well as domestic shorthairs.

The Singapura is thought to have inherited this disease from Abyssinian progenitor cats in its development.

The anaemia it causes is often intermittent, so is not always detected on a one-off red cell count (a type of basic blood test).

Generally an affected cat will suffer a mild anaemia, or a gradually developing anaemia that she will have time to adapt to, and so may not show any signs of disease.

In these cases, although the condition is present from birth, it may not be diagnosed until the cat is quite old.

Sometimes affected cats may suffer from acute, life-threatening bouts of anaemia.

Signs of anaemia include pale gums (and other mucous membranes), lethargy, weakness, increased respiratory rate as well as possible jaundice (yellowing of the gums and whites of the eyes) and enlargement of the abdomen.

Not all PK deficient cats develop clinical signs of anaemia.

There is no cure for PK deficiency.