Polycystic Kidney Disease (PKD)

Polycystic Kidney Disease (PKD), also named autosomal dominant PKD, is characterized by variously sized, fluid-filled cysts in the renal cortex and medulla with hepatic and pancreatic cysts also possible. The cysts develop from birth and enlarge with age. The cysts destroy the renal parenchyma and disturb renal function, eventually causing renal failure. Affected cats present with signs of renal insufficiency such as weight loss, decreased appetite, increased drinking and urination, poor body condition, and vomiting. Biochemical labwork and ultrasonography examination are helpful tools in identifying the severity of disease within an affected individual. An autosomal dominant point mutation in the PKD1 gene has been identified as the most common genetic mutation for the disease. No homozygous cats have been identified, suggesting the mutation is a homozygous lethal mutation in utero. PKD is very common in Persian and Persian-related cats, affecting approximately 38% of Persian cats worldwide. While there is no known sex linkage to the inheritance of the mutation, research has shown male cats have a higher prevalence of the mutation.

There is no treatment specific for feline polycystic kidney disease. As the symptoms are similar to patients with feline chronic kidney disease, therapy is guided towards the same supportive care methods such as special diets, fluid therapy, medications to reduce nausea and to block absorption of phosphorus, along with other support options for feline kidney failure.

There are many responsibilities to consider when breeding cats. Regardless of test results it is important that your cat is in good general health and that you are in a position to care for the kittens if new responsible owners are not found. For first time or novice breeders, advice can be found at most cat registry websites.

This disease is autosomal dominant meaning that one copy of the mutation is needed for disease signs to occur. Use of cats with one or two copies of the disease mutation is not recommended, as there is a risk that the resulting litter will contain affected kittens. For example if a cat with one copy of the PKD mutation is bred with a clear cat with no copies of the PKD mutation, about half of the kittens will have one copy and half will have no copies of the PKD mutation. Please note: It is possible that disease signs similar to the ones caused by the PKD mutation could develop due to a different genetic or clinical cause.