A recent story in online news media about a female Sphynx cat that was bred to exhaustion in giving birth to around 90 kittens and making their owner about £140,000, drew me into doing research about kidney disease in Sphynx cats because the report says that if a breeder over-breeds a cat, they can develop kidney disease. I couldn’t find any research to support that contention but I did bump into a story on a Sphynx cat forum about a male Sphynx cat, Tommy, who at 4 years old was dying of kidney disease.
That is a very early age to develop kidney disease. The owner was asking whether any other Sphynx owner had the same experience (can anyone help here?). The woman’s veterinarian had diagnosed Fanconi syndrome, which is a form of kidney disease in which the kidneys shed glucose and protein.
It is usually or perhaps exclusively acquired rather than inherited. Some cats are predisposed to kidney disease through inheritance in their genes but this is not the case in this instance. Fanconi syndrome is normally caused by drugs.
One of those drugs is chlorambucil, which is an immunosuppressive and anti-cancer medication used to treat certain cancers such as leukaemia, lymphoma, multiple myeloma and others. It can also be used to treat inflammatory bowel disease in cats. It is off label or extra label and therefore not created to treat cats but nonetheless it is used to treat cats under careful veterinary supervision.
A study dated July 13, 2015, entitled Acquired Fanconi Syndrome (FS) in Four Cats Treated with Chlorambucil, assessed 4 cats with acquired FS. They had been treated for alimentary lymphoma or inflammatory bowel disease with chlorambucil and corticosteroids.
When the chlorambucil therapy was discontinued, within three months there was partial or complete resolution of Fanconi syndrome in three of the four cats. This, on my interpretation, supports the view that chlorambucil causes Fanconi syndrome. Cats treated with this drug should be monitored for the development of glucosuria which describes the presence of glucose in the urine.
My research also brings to mind the question as to whether Sphynx cats can suffer from early kidney disease. We know it’s common in older cats but does this very common disease affect Sphynx cats earlier than in other cat breeds or the general cat population?
The screening for Fanconi syndrome is apparently simple as it entails a urine analysis. If it throws up protein and glucose even in trace amounts when blood glucose is normal it is indicative of Fanconi syndrome. Please note that I’m not a veterinarian and this article is written on the basis of research on the Internet.
Below are some more pages on kidney disease.