Persian cats: kidney disease, PKD and what to watch for

What health problems are Persian cats known for?

Kidney disease is the big one. Cornell Feline Health Center says polycystic kidney disease occurs most often in Persians, and less often in Himalayans and British Shorthairs. A 2004 UC Davis study estimated that PKD affects about 38% of Persian cats worldwide, which made it the most common inherited disease in cats at the time.

Kidney trouble also shows up in how Persians die. A 2019 study of 3,235 Persians seen at UK general practices found renal disease was the most common grouped cause of death, at 23.4%. The same study found that 64.9% had at least one disorder recorded.

What is PKD in cats?

PKD is an inherited disease where small, closed, fluid-filled sacs grow in the kidneys. Cornell says the cysts are present at birth. Over time they grow and multiply, crowd out healthy tissue and often lead to kidney failure.

It is passed on through one faulty copy of a gene called PKD1. The UC Davis Veterinary Genetics Laboratory says a cat with one copy is affected, and each kitten has about a 50% chance of inheriting it. Cats with two copies are thought not to survive, so you will rarely see them. The lab adds that cysts often appear before 12 months of age, while kidney failure usually comes later.

Warning signs of kidney disease in a Persian

Early on there are often no signs at all, because the body makes up for the loss. Cornell says PKD signs usually match general kidney disease and are most often noticed around age seven, though some cats show them years earlier or later.

• Drinking more and peeing more
• Eating less and losing weight
• Nausea or vomiting
• Low energy and an unkempt coat
• Pale or white gums, which can mean anemia
• Sudden changes in sight, wobbliness or confusion, which can come from high blood pressure. See a vet the same day.
• A cat that stops eating, even for a short time. Call your vet today.

Is there a gene test for Persian cats?

Yes. The UC Davis lab offers a PKD1 DNA test for Persians and breeds with Persian ancestry, such as Exotic Shorthairs and Himalayans. You collect cells by gently brushing the inside of your cat's cheek with swabs. The lab says frequency has dropped in many catteries that used ultrasound screening and better breeding.

A gene test tells you if your cat carries the PKD1 change. It does not tell you how badly the kidneys are affected. Cornell says ultrasound is the only way to get a definite diagnosis, since the cysts usually cannot be felt or seen on X-rays. If you are buying a kitten, ask the breeder for the parents' PKD1 results in writing.

What will my vet do for a Persian with kidney disease?

Your vet will test, stage the disease and then work to slow it down. PKD cannot be reversed, and draining the cysts is not practical because there are too many and they refill. Care follows the same plan as other kidney disease in cats.

• Blood tests for creatinine and SDMA. Cornell says SDMA rises earlier, at about 40% loss of kidney function.
• A urine test, including protein in the urine and a check for infection
• Blood pressure checks. About 60% of cats with chronic kidney disease develop high blood pressure.
• An ultrasound of the kidneys
• A kidney diet, which has been linked to longer survival
• Help with hydration, such as wet food, more water bowls, or fluids under the skin
• Medicines for high blood pressure, anemia, nausea or appetite

Can peptides help a Persian's kidneys?

No one knows, and that matters. No clinical trial of BPC-157, TB-500, GHK-Cu or KPV in cats appears in PubMed. A PubMed search for BPC-157 in cats returns no results at all. None of these peptides is approved by FDA for cats. Most vials are labelled "research only" and are not checked by FDA, so the label may not match what is inside.

Kidneys clear many substances from the body, and nobody has published how a cat with failing kidneys handles any of these products. The bigger risk is delay: time spent on an untested vial is time without a kidney diet, fluids or blood pressure control. Read what is and isn't known about safety and talk to your vet before you give anything.

Questions to ask your vet about your Persian

Take this list to your next visit. It helps you get a plan that fits your cat's age and test results.

• Should my cat have a PKD1 gene test, a kidney ultrasound, or both?
• Which blood and urine tests should we repeat, and how often?
• Is my cat's blood pressure normal?
• Would a kidney diet help now, and how do I switch safely?
• How are my cat's teeth and gums, and does anything need treating?
• Which signs mean I should call you the same day?