— By Dr. Henri Bianucci, Board-Certified Veterinary Surgeon
If your cat used Ancestry.com, it would learn that its roots are in the Near and Middle East. Its ancestors are known as the Near Eastern Wildcat, which still roam the deserts there. These wild cousins and your kitty share a common ancestral line.
I (Henri Bianucci) recently read a landmark study co-authored by Stephen O’Brien of the National Cancer Institute in Frederick, Maryland, that says cats and humans began to co-habitate as mankind shifted from hunter-gatherer to farming societies about 10,000 years ago.
O’Brien goes on to explain that cats were probably not captured and forced into domesticity. Rather he postulates that it was a genetic variation in a particular line of wildcat that prompted them to “experiment” with living alongside humans.
It is not hard to imagine that human villages produced many byproducts that were appealing to some of the cats' favorite dinner items, such as rats and mice. Humans received free rodent control, and the cats found readily available food sources. It was mutualism at its best.
The domestic house cats in our society may still pick off a mouse, rat or bird, but most of their meals now come from a bag or a can. This major change in diet is being imposed upon an animal that was highly adapted to desert life.
One major adaptation is the exquisitely efficient feline kidney. It is a finely tuned but delicate, water-conserving machine. This is a highly specialized adaptation that allows them to thrive in one environment, but may predispose them to problems in another.
It’s like going off-road driving in a Ferrari. The cat is an obligate carnivore. That means it has to have meat to survive, and that’s virtually all it eats in the wild. If you look at the ingredients in most cat foods, you will find they are loaded with plant-based material.
Simply stated, meat protein results in the formation of acidic urine, while plant-based diets result in alkaline urine. This is important, because many kidney stones, which commonly affect cats, form only in alkaline urine. This factor, combined with the mineral content of today’s cat food, has made kidney stone formation a pervasive problem in cats.
When a kidney stone forms, it may reside harmlessly in the kidney for years. But if that stone passes into the cat’s ureter, the tube that flows to the bladder and which is not much wider than a human hair, it can totally obstruct the flow of urine. This obstruction can result in the destruction of the affected kidney in a matter of days.
Even if you remove the stone, there are often others lurking in the kidney that will soon pass and create more obstructions. This situation has created the need for yet another adaptation to human-feline co-habitation. And in a recent surgery, we saw just that.
Milton is an 11-year-old orange tabby, and his life was hanging by a thread. His right kidney had been obstructed in the past, and the event was unnoticed. The result was complete loss of function in that organ. Recently, his only remaining kidney was obstructed by a kidney stone, putting him into renal failure and at risk of a total and permanent loss of kidney function. The obstruction was inaccessible, and other stones were likely present. The solution was an innovative new procedure known as a “SUB.”
Basically this is a device that bypasses the ureter and connects the kidney directly to the bladder. Specifically, a catheter is placed into the kidney and is connected to a titanium chamber that is placed under the skin, or the SUBcutaneous space.
This chamber, which can be flushed easily to clear subsequent stones or debris, is then connected to another catheter that flows into the bladder.
Within 36 hours, Milton's kidney status was completely normal, as he rubbed his face against his cage door soliciting attention. If not a miracle, it’s at least a medical marvel and a testament to the depth of the relationship between humans and cats.
Dr. Henri Bianucci and Dr. Perry Jameson are with Veterinary Specialty Care LLC. Send questions to petdocs@postandcourier.com.
