What Is Polycystic Kidney Disease?
Polycystic kidney disease (PKD) is an inherited disorder in which fluid-filled cysts slowly replace normal kidney tissue. In cats it is caused by a dominant mutation in the PKD1 gene and is most common in Persian cats and related breeds such as Himalayans, Exotic Shorthairs, and some British Shorthairs and Ragdolls with Persian ancestry. A single copy of the mutation is enough for a cat to develop cysts.
PKD is not the same as ordinary chronic kidney disease in cats or the broader topic of cat kidney disease. Those pages cover age-related and other acquired kidney failure. PKD is a specific genetic cause that can lead to chronic kidney failure later in life, usually in middle age, as enlarging cysts crowd out working kidney tissue.
Why it matters
Many affected cats look healthy for years. Genetic testing before breeding, and ultrasound screening of Persians and related breeds, stop the mutation from spreading and catch kidney changes early.
Signs Owners Notice
- Often none in young adult cats — cysts can be silent for a long time
- Increased thirst and urination as kidney function declines
- Weight loss, reduced appetite, and vomiting in later stages
- Lethargy and a poor coat
- Occasionally enlarged kidneys felt by a vet during a physical exam
Diagnosis
A DNA test on a cheek swab or blood sample detects the PKD1 mutation and is the preferred screening tool for breeding cats. Abdominal ultrasound can show cysts in the kidneys (and sometimes the liver) from about 10 months of age onward, though tiny early cysts can be missed. Once kidney function falls, bloodwork and urine tests look like other forms of chronic kidney disease: rising creatinine and SDMA, dilute urine, and sometimes high blood pressure.
PKD should be distinguished from acquired cysts, kidney infection, and protein-losing nephropathy, which damages the kidney filters rather than filling the organ with genetic cysts.
Treatment and Outlook
- No cure for the cysts: treatment focuses on slowing kidney decline and keeping the cat comfortable, the same supportive approach used for CKD.
- Kidney-supportive diet: veterinary renal diets help once azotemia appears.
- Fluids, blood pressure control, and phosphate binders: used as staging and lab results require.
- Monitoring: regular bloodwork, urine checks, and blood pressure measurements guide care.
- Breeding advice: cats that test positive for the PKD1 mutation should not be bred.
Cats with only a few small cysts may live a normal lifespan. Cats with progressive cyst growth often develop kidney failure in middle age; survival then depends on how early CKD care starts and how the individual responds. Ethical breeding has already reduced PKD frequency in some Persian lines.
Practical Tips for US Pet Owners
- Ask for a PKD DNA result before buying or adopting a Persian-related kitten; see pet DNA testing.
- Schedule screening ultrasound for adult Persians and related breeds if DNA status is unknown.
- Watch for increased drinking — the same early clue as other kidney disease.
- Find a nearby practice through veterinary clinic listings.
When to see a vet
Book a visit if your Persian-related cat drinks or urinates more, loses weight, or vomits repeatedly. Ask about PKD screening at a routine wellness visit if the breed is at risk.
Key Takeaways
- Feline PKD is an inherited cyst disease, especially in Persians and related breeds.
- DNA testing and ultrasound screening identify affected cats before breeding.
- Care mirrors CKD support once kidney function declines; there is no surgery that removes all cysts.
FAQ
Can mixed-breed cats get PKD?
Yes, if they inherited the PKD1 mutation from a Persian-related ancestor, but it is far more common in Persians and closely related breeds.
Is PKD painful?
The cysts themselves are not usually described as painful, but advanced kidney failure causes nausea, dehydration, and feeling unwell.
Is there a vaccine or medicine that stops cysts from forming?
No. Prevention is genetic testing and responsible breeding; treatment is supportive kidney care.