What is Feline Pyruvate Kinase Deficiency

Feline Pyruvate Kinase Deficiency (Feline PkDef) is a hereditary genetic disorder found in cats, specifically in breeds like Maine Coons. It is caused by a mutation in the PKLR gene, which is responsible for encoding the enzyme pyruvate kinase. Pyruvate kinase is involved in a crucial step of glycolysis, the process by which cells produce energy from glucose.


Feline PkDef is inherited in an autosomal recessive manner. This means that a cat must inherit two copies of the mutated gene (one from each parent) to exhibit the disorder. Cats that inherit only one copy of the mutated gene are carriers and typically do not show any symptoms. When two carriers are bred together, there is a 25% chance of producing an affected kitten, a 50% chance of producing a carrier kitten, and a 25% chance of producing an unaffected kitten.


The primary issue in cats with Feline PkDef is a deficiency of pyruvate kinase enzyme, which leads to a reduced ability of red blood cells to generate energy. This results in hemolytic anemia, a condition where red blood cells are destroyed faster than they can be produced, leading to anemia, jaundice, lethargy, and other associated symptoms.

Options for Resolutions

Breeding Decision - Broken Allele Carrier and Non-Carrier Pairing

 It is generally considered acceptable to breed a cat that carries one copy of the mutated gene (broken allele carrier) to a cat that does not carry any copies of the PkDef gene. This is because the offspring from this pairing will inherit only one copy of the mutated gene, making them carriers but not affected by the disorder. As long as the non-carrier cat is from a well-screened lineage and has no other hereditary health issues, this breeding combination can help maintain genetic diversity in the breed while reducing the risk of producing affected kittens.

However, responsible breeding practices also involve transparency. Breeders should inform potential cat owners about the genetic status of the kittens and educate them about the disorder. It's important to prioritize the health and well-being of the cats while preserving the characteristics of the breed.

Anemia in felines refers to a condition where there is a decrease in the number of red blood cells (RBCs) or a reduced concentration of hemoglobin in a cat's blood. Hemoglobin is a protein within RBCs that carries oxygen from the lungs to the body's tissues and helps remove carbon dioxide. Anemia in cats, as in humans, can result in insufficient oxygen delivery to cells and organs, leading to a range of symptoms and potential health issues.

What Causes Anemia in Cats?

Symptoms of Anemia in Cats

Diagnosis and Treatment

If you suspect your cat is anemic, it's essential to consult a veterinarian. Diagnosis involves a physical examination, blood tests to measure RBC count, hemoglobin levels, and other relevant parameters. Treatment depends on the underlying cause and severity of the anemia. It might involve addressing nutritional deficiencies, managing underlying conditions, controlling bleeding, administering medications, blood transfusions, or other interventions as needed.

Prompt veterinary care is crucial to identify the cause of anemia and initiate appropriate treatment to improve your cat's overall health and well-being.

What is an Enzyme?

An enzyme is a type of protein that acts as a biological catalyst in living organisms. Catalysts are substances that facilitate chemical reactions by lowering the activation energy required for the reaction to occur. Enzymes play a fundamental role in a wide range of biological processes, making them essential for the functioning of cells, tissues, and organs.

Enzymes are highly specific in their actions, and each enzyme typically catalyzes a specific chemical reaction or a group of closely related reactions. They function by binding to specific molecules called substrates, and then they facilitate the conversion of these substrates into products. Enzymes themselves are not consumed or altered during the reaction; they can be reused to catalyze multiple rounds of the same reaction.

The structure of an enzyme is crucial to its function. Enzymes have an active site—a specific region where the substrate(s) bind. The active site has a precise three-dimensional shape that complements the shape of the substrate molecules, allowing them to fit together like a lock and key. This interaction between the enzyme and its substrate(s) enables the enzyme to stabilize the transition state of the reaction, which ultimately lowers the energy barrier required for the reaction to proceed.

Enzymes are essential for almost every biological process, including:

Enzymes are highly sensitive to changes in temperature, pH, and other environmental conditions. Their activity can be influenced by factors that affect their three-dimensional structure. In some cases, enzymes require additional molecules, called cofactors or coenzymes, to function properly. Enzymes are crucial components of biological systems, acting as catalysts that accelerate specific chemical reactions necessary for life. Their specificity, efficiency, and ability to regulate reactions are key features that allow cells and organisms to function effectively.