Page 24 - Boca Club News - September '23
P. 24
Page 24, Boca Club News
Nature & Pets
You and Your Pet:
Kidney Transplants for Cats and Dogs
By Margaret Johnson DVM, Calusa Veterinary Center, usually given every other day long term. Medication costs
6900 Congress Avenue, Boca Raton, FL 33487, (561) for dogs can vary from $150 per month to $2000 per month
999-3000. www.CVCBoca.com. depending on the dog’s size.
Kidney transplants are something everyone has heard What are potential complications to the recipient?
of for people, but may be confined to specialized facilities There are basically three main complications:
with experienced surgeons, Successful kidney transplants • Infection from the immune-suppressive therapy is the
in cats have been going on since the mid-1980s. Canine second most common cause of transplant-associated death
programs have been less successful, but are also available (rejection being the first). In cats, Toxoplasma infection is
in limited facilities. of particular concern and, while preoperative testing may
To the uninitiated, the impression may be that once have already been negative, some cats turn positive after
someone receives a new kidney, life is renewed and all the immune suppression begins. Also in cats, old viral
the kidney problems are solved. In fact, this is hardly the upper respiratory infections can be expected to recur and
case. There are immune-suppressive medications needed to they can be severe. In dogs, life-threatening infections can
prevent the new organ from being rejected, not to mention emerge in any organ system.
potential for infection, on-going screening tests and other Ollie and Mr. Moto now live together after one cat’s kidney • Stricture (narrow scarring) of the ureter, which is
issues. A kidney transplant is a very big deal regardless was transplanted into the other. Photo courtesy of Dr. Lillian the tiny tube that carries urine from the new kidney to the
of the species, and not every patient is even a candidate, Aronson. urinary bladder. If this occurs, another surgery is needed to
so let’s walk through the main considerations. trim the scarred area and re-attach the ureter to the urinary
Where do the donors come from and what happens the new kidney occurs when levels dip below 200 ng/ml.) bladder. The original kidneys are generally not removed
to them afterwards? This question is important ethically Cyclosporine has some disadvantages that include: unless there is a reason to do so. The new kidney is simply
for everyone involved in the transplantation program. • Expense. Cyclosporine is expensive. Concurrent an extra one. There is an approximately 21% incidence of
No one wishes to harm the donor animal who cannot administration of ketoconazole, a medication normally this complication in the first 62 days post-operatively in
voluntarily become an organ donor in the way a human can, used to treat fungal infection, has an added benefit cats. Mostly males are affected.
nor is there a mechanism to harvest organs from comatose of “potentiating” cyclosporine. This means that less • The risk for developing diabetes mellitus increases
brain-damaged patients as might be done for humans. cyclosporine is needed to achieve the desired effect. If by approximately five times after a kidney transplant.
Feline kidney donors usually come from research ketoconazole is well tolerated, a substantial financial What kind of survival time can you expect? In a
facilities. These cats are classified as “specific pathogen savings can be realized. Additionally, if ketoconazole is recent study of feline kidney transplants, 59% of renal
free,” which means they are free from infectious diseases. used, it may become possible to dose the patient only once transplant patients were still alive six months after
They are matched by blood typing, and potentially by a day rather than twice. Approximately 30% of transplant surgery and 41% were still alive three years afterwards.
tissue-typing depending on the transplant program. A patients will not be able to utilize this protocol due to the Apparently the first six months are a somewhat crucial
research cat is selected and a kidney removed for the development of excessive cyclosporine levels or liver time in determining long-term survival.
recipient. After the procedure, the owner of the recipient enzyme elevations from the ketoconazole. The University of Wisconsin Renal Transplant Center
cat must adopt the donor. • Expenses for Monitoring. Periodic blood level reports 70% survival at six months for cats and 50%
Some transplantation programs allow the owner of the monitoring is needed to check that the right dosage is being survival at three years. Of the cats that survived to be
recipient cat to provide the donor. Donors must be young used. For most drugs, “what you swallow is what your discharged from the hospital (i.e., they did not succumb
adults, generally at least 10 pounds in size, be free of body gets.” For other drugs, there are individual variations to problems directly related to the surgery), 96% survived
infectious diseases such as feline immunodeficiency virus, in how the medication is absorbed, and cyclosporine is one. to six months.
feline leukemia virus and toxoplasmosis, and must have When two patients take the same amount of cyclosporine, In dogs, the picture is not nearly as bright. The
excellent kidney function. Basic blood testing and urine they may not achieve the same serum levels; some University of California at Davis program was seeing
cultures must be normal. individual fine-tuning is needed. about a 40% success rate.
You enter the program with one cat and leave with • Long-term use of cyclosporine increases the risk for Kidney transplantation is an expensive undertaking. The
two cats. For dogs, the owner of the recipient is generally the development of cancer, specifically lymphoma. At the University of California at Davis program, for example,
responsible for finding the donor. The University of California University of Wisconsin Renal Transplant Center, a 14% required a deposit of $11,000 for cats and $13,000 for
transplant program has been on hold since 2007, but as an incidence of malignant tumor development is reported for dogs. Transplantation involves the adoption of a donor and
example their former donor guidelines were that the donor cats with post-transplant time (and thus cyclosporine use long-term medication and blood testing for the recipient.
must be less than six years of age, of similar size as the time) of greater than one year. If this is something you are seriously considering, be sure
recipient (and preferably of the same breed), and if the donor In dogs, the chemotherapy agent azathioprine is also to discuss the procedure with the transplant center closest
is not related to the recipient tissue matching is needed. regularly used for its immuno-suppressive properties. It’s to you, as well as with your regular veterinarian.
What kind of home care will the recipient require?
The recipient is going to require suppression of his immune
system for the rest of his life. This not only requires a
substantial financial commitment for the medication but
also the ability to give the cat oral medication at least
twice a day for the rest of his life. The heart of this therapy
is a medication called cyclosporine, a medication that
has revolutionized organ transplantation for humans.
Prednisone, a commonly used cortisone derivative, is
typically used as well, at least to start.
Cyclosporine is typically given twice a day with the
lowest blood level of the day being approximately 500 ng/
ml around the time of surgery and lowering to 250 ng/ml
after a month or so of recovery after surgery. (Rejection of