A New Cause for Some Cases of Feline Kidney Disease?
We talked recently about canine distemper and feline distemper and how the former is caused by a morbillivirus while the later, despite also being called “distemper,” is actually caused by a parvovirus. New research has shown that cats have their own type of morbillivirus after all and that it might be associated with a particular type of kidney disease.
Scientists in China recently reported finding this new morbillivirus in cats and have linked it to the development of tubulointerstitial nephritis (TIN). If further research confirms this connection, we may be closer to understanding why so many cats suffer from kidney disease as they age. The study appeared in the Proceedings of the National Academy of Sciences.
Now, there are some subtleties here that we need to understand before diving into the research. First of all, tubulointerstitial nephritis is just one type of kidney disease in cats. When you think feline kidney disease, your thoughts probably immediately leap to chronic kidney disease (CKD or chronic kidney failure as it is sometimes called). CKD is the end result of long-term kidney damage, and that damage can be caused by one or more insults, alone or in combination. Toxins, episodes of low blood pressure, infections, immune disorders, the wear and tear of a long life, etc. can all be to blame.
Tubulointerstitial nephritis is a type of kidney disease that is characterized by inflammation of the kidneys’ tubules (the small tubes that carry liquid filtered from the blood) and the spaces in between them. In people, the acute form of the condition is often caused by infections or allergic drug reactions, but up until now, we have rarely been able to pinpoint a cause in cats. However, the take home message of this new study is not that a virus is to blame for all (or even most) cases of chronic kidney disease in cats. It might be playing an important role in some instances, however.
So what the researchers did was take samples from 457 stray cats in Hong Kong and mainland China. Of the cats tested, 12.3% were infected with this new feline morbillivirus. That doesn’t sound like a huge number, but 27.8% of the cats had antibodies to the virus, indicating that they had been infected in the past. Even more interestingly, when the scientists examined 27 stray cats that died, they found that of the 12 that had been infected with the virus, 7 had TIN while only 2 of the uninfected cats had kidney disease. They also found direct evidence of the virus in feline kidney cells.
Like I said, I don’t want you walking away from this post thinking that this new virus causes all cases of chronic kidney disease in cats, but how exciting would it be if in the future we had a vaccine that could protect at least some of our pets from this devastating disease?
Dr. Jennifer Coates