Cat kidney transplants: For some, the pricey procedure is well worth it

So when “Despy” suddenly developed a congenital form of advanced kidney disease at age 2 and the veterinarian estimated his life span in months, Segal vowed to do whatever he could to save the cat. “He took care of me when I was sick,” says Segal, a software developer who lives in San Jose. “It was my turn to take care of him. It’s that’s simple.”

Segal, then living in the Boston area, drove his cat to the University of Pennsylvania School of Veterinary Medicine in Philadelphia where Despy underwent a kidney transplant in 2018. Today, Despy is thriving. So is Stevie, the kidney donor cat from a local shelter that Segal agreed to adopt as part of the renal transplant. He adores them both. “They play together, they groom each other, they roughhouse,” Segal says. “We’ve become a comfortable, loving family.”

Chronic kidney disease is one of the most common conditions in aging cats and a leading cause of death. The disease can be heritable, afflicting young cats such as Despy, and can result from toxin exposure, such as eating lilies. (A cat who eats even a small amount from any part of a lily plant can suffer fatal kidney failure within days.)

Like humans, cats have two kidneys, which filter waste from the body, and can live with just one if that kidney is healthy.

Kidney transplants in cats began more than 25 years ago, although they still are rare, and only three facilities perform them: Penn Vet, the University of Wisconsin School of Veterinary Medicine and the University of Georgia College of Veterinary Medicine.

Penn Vet has performed 185 transplants since 1998, the Georgia school more than 40 since 2009, and Wisconsin 87 since 1996.

Not all cats are candidates for the procedure, and for those who are, it can be expensive, up to $25,000 for the surgeries to retrieve the donor kidney and transplant it into the recipient cat. Yet the surgeons who do them say they find it personally gratifying to give people more time with their cherished companions. Also, they add, the surgeries and long-term follow-up in cats can provide knowledge that potentially can benefit human health.

Most cats gain an average of two to three years, although there are exceptions. Despy, for example, is six years post-transplant. “Our longest survivor was nearly 13 years,” says Chad Schmiedt, the Alison Bradbury chair in feline health at the Georgia veterinary school. “Shilo was 3 when we did the transplant in June 2009 and lived until April 2022.”

About 40 percent “go out three years post-transplant,” says Robert J. Hardie, clinical professor of small-animal soft-tissue surgery at the Wisconsin veterinary school, adding that survival often depends on whether postsurgical complications occur. “Some live longer. We’ve had some out 10 years.” At Penn Vet, up to 70 percent are alive and doing well one year after transplant, and two recipients lived 13 years after the surgery.

“It is a life-expanding procedure with the possibility of relatively good outcomes — sometimes dramatic outcomes — in terms of longevity that is of great value to many pet parents,” Hardie says. Moreover, scientists could learn more about immunosuppression in cats that could be applicable to humans, he says.

Lillian Aronson, professor of surgery at Penn Vet — who performed Despy’s transplant — agrees. “Cats are a natural living model of kidney disease,” she says, and their shorter life spans can make information available more quickly than from humans.

Many pet health insurance companies will cover some of the costs for the recipient, but usually not for the donor because “the donor is not the insured pet,” according to the North American Pet Health Insurance Association. The cost for the donor surgery to harvest the kidney is about 25 percent of the $25,000 total, Aronson says.

Still, some pet parents are devoted to their cats and don’t hesitate. “We don’t question someone who spends $40,000 for a car,” Aronson says. “One of my clients said: ‘I just spent $17,000 on my roof, and I love my cat a lot more than my roof.’”

The cats getting new kidneys typically are between the ages of 8 and 12, although younger cats without other potentially serious medical conditions often do better and live longer, experts say. Schmiedt usually won’t perform a transplant on a cat older than 16. Hardie says the oldest cat transplanted at Wisconsin was 18. Aronson once did one on a nearly 18-year-old who had no other health problems and was youthful in behavior and who lived for another two years with the new kidney.

Cats with moderate kidney disease are better candidates than those with mild or advanced disease, because of the balance between surgery risks and benefits, although age provides an advantage for young cats who may have advanced kidney disease. The cats also can’t have chronic infections or cancer because they must take the immunosuppressive drug cyclosporine for life, which can worsen both conditions. Severe heart disease also rules them out. “You want a recipient who has the best chance of making it” through surgery and beyond, Schmiedt says.

Matching is easier for cats than it is for humans needing a transplant because there are only two blood types among all cats.

Donors come from cat research breeding facilities or shelters, where they might otherwise have a bleak future, and families whose cats undergo transplants must adopt the donors. “For the cost of a kidney, [the donor cats] get to move in with a cat-loving household and are universally loved by their new adoptive families,” Schmiedt says.

Andy and Eleni, financial consultants from Gainesville, Fla., who spoke on the condition that their last names not be used for privacy reasons, embraced their second cat, Pappy, after Teenie’s operation six years ago at the Georgia facility. Teenie was 8 years old when kidney failure meant he would need a new one to survive; he is now 14. Pappy was 2 when he donated his kidney and is now 8.

“The surgery not only gave us more time with a cat we love, but we were also blessed with a wonderful new cat who saved his life and brought an equal amount of joy and love into ours,” Andy says.

During surgery, the team removes the new kidney from the donor, then stitches it into the recipient. They suture the donor blood vessels — the renal artery and vein — to the aorta and vena cava of the recipient and attach the donor ureter to the recipient’s bladder.

They usually leave the old kidneys in place as a reserve, in case the new kidney doesn’t work right away. Many cats, however, urinate immediately, even while in surgery. “It’s always exciting the first time they pee,” Schmiedt says.

The surgeries can take up to eight hours. The donor can go home in a few days, while the recipient typically stays longer, sometimes a week or more. Both cats are followed for life.

Transplants other than kidneys in pets aren’t viable because most require the death of the donor. Kidney transplants in dogs can be challenging because, unlike cats, they often suffer problems with immunosuppression, says Aronson, who has performed three. (The dogs survived but did not do as well long-term as cats, she says.)

Although post-transplant complications can occur, research suggests that cats in renal failure can do well — if they are good candidates for the procedure. “I think transplantation is the only real way to cure kidney disease” in cats, Schmiedt says. “The goal is to give them the quality of life they had before.”

This seems to be true for Despy. “He has all the energy he’s ever had,” Segal says. “He’s living his best life.”