Feline Pyruvate Kinase Deficiency (PKD) is a rare inherited disorder that affects a cat’s red blood cells. This condition causes a deficiency in pyruvate kinase, an enzyme that plays a vital role in creating red blood cells. Without enough of this enzyme, the red blood cells become unstable and fragile, leading to their premature destruction.
PKD is inherited as an autosomal recessive trait, which means that cats must inherit two copies of the defective gene, one from each parent, to have the disease. Cats with only one copy of the gene are carriers and don’t have any symptoms of PKD but can pass the gene on to their offspring.
Symptoms of Feline Pyruvate Kinase Deficiency
The symptoms of PKD vary depending on the severity of the disease. Some cats will develop symptoms early in life, while others might not have any signs until later in adulthood. Symptoms include:
- Anemia
- Lethargy
- Jaundice
- Pale gums
- Rapid breathing or panting
- Weight loss
- Enlarged spleen
- Blood in their urine or feces
Diagnosing Feline Pyruvate Kinase Deficiency
Diagnosing PKD involves a combination of clinical signs, blood tests, and genetic testing. Blood tests might reveal anemia, low red blood cell count, and elevated levels of bilirubin (a waste product produced by red blood cells breaking down). Genetic testing can confirm the presence of the defective gene responsible for PKD.
Stages of Feline Pyruvate Kinase Deficiency
There are three stages of PKD in cats, which are determined by the severity of the condition and the progression of symptoms:
Early Stage:
In the early stage, cats might not have any symptoms of PKD or might have mild symptoms such as lethargy or pale gums. Blood tests can reveal a low red blood cell count and elevated bilirubin levels.
Intermediate Stage:
In the intermediate stage, cats will likely have more severe symptoms such as anemia, jaundice, rapid breathing or panting, weight loss, and an enlarged spleen. Blood tests might reveal a further decrease in red blood cell count and higher levels of bilirubin.
Advanced Stage:
In the advanced stage of PKD, cats can have life-threatening symptoms such as severe anemia, blood in their urine or feces, and difficulty breathing. Their spleen could become enlarged to the point where it causes discomfort and pain. At this stage, treatment options are limited, and the focus is on managing symptoms to improve your cat’s quality of life.
Treating Feline Pyruvate Kinase Deficiency
Currently there is no cure for feline PKD. Treatment options focus on managing symptoms and improving your cat’s quality of life. In the early stages of the disease, treatment could involve regular blood transfusions to replace the damaged red blood cells. However, repeated transfusions can cause their own set of complications, such as transfusion reactions and the development of antibodies against transfused blood. In more advanced cases, surgical removal of their spleen (splenectomy) might be necessary to alleviate symptoms caused by an enlarged spleen.
Preventing Feline Pyruvate Kinase Deficiency
The best way to prevent feline PKD is through responsible breeding practices. Breeders should screen their breeding cats for the presence of the defective gene and only breed cats that don’t carry the gene. Genetic testing can be performed to identify carriers and affected cats. It’s recommended that all cats with a known family history of PKD undergo genetic testing before being used for breeding purposes. By preventing the defective gene from being passed onto future generations, the amount of cats born with PKD can be reduced. It’s also important for cat owners to educate themselves about the disease and work with their veterinarian to monitor their cat’s health and catch the early signs of PKD.