Feline Lower Urinary Tract Disease
Feline lower urinary tract disease, also called feline urologic syndrome (FUS), is the most common disorder affecting the lower urinary tract in cats. The lower urinary tract is the urinary bladder, bladder sphincters, and urethra. Therefore, conditions affecting any of these organs can cause FLUTD. Cystitis, meaning inflammation of the bladder, is another term commonly used, but should be specifically reserved for conditions affecting only the urinary bladder.
Lower urinary tract problems are by far the major health concern of cat owners-although they do not occur in most cats. One reason is that FLUTD has a 50 to 70 percent rate of recurrence. Although FLUTD can occur in cats of all ages, it is seen most commonly in those older than 1 year. It occurs in both sexes, but the anatomy of the male increases the likelihood of bladder obstruction. It is more common in obese cats, possibly due to mechanical interference with voiding or to infrequent voiding in a less active cat.
The signs of FLUTD include prolonged squatting and straining; entering and leaving the litter box often, sometimes without voiding; frequent urination; passing bloody urine; urinating in unusual locations (possibly because the litter box becomes associated with pain); licking the penis or the vulva excessively; and crying out during the act of voiding.
FLUTD accounts for the great majority of feline urinary tract symptoms (dysuria, hematuria, and anuria), and although the signs of FLUTD might suggest a bladder or urethra infection, studies have shown that in most cases a bacterial infection is not present-at least not initially.
Causes of FLUTD
There are a number of important contributing factors that explain why some cats get FLUTD, but no one circumstance accounts for all cases. It is known that
In summary, no one theory accounts for all cases of FLUTD. It does seem likely that reduced water intake, diets that contain large amounts of such crystal precursors as magnesium and calcium, urinary pH, as well as other currently unknown factors all contribute. Bacterial infection, once established, is an important cause of recurrent attacks.
This article is excerpted from “ Cat Owner’s Home Veterinary Handbook” with permission from Wiley Publishing, Inc.
Copyright © 2008 by Delbert Carlson, DVM, and James M. Giffin, MD. All rights reserved.