Feline Lower Urinary Tract Disease: New Name, Same Disease
Stephen Sheldon, D.V.M.

That’s right folks, F.U.S, or feline urological syndrome, has now been renamed Feline Lower Urinary Tract Disease, or FLUTD. Personally, I always liked FUS, it roles off the tongue much easier than FLUTD. Why in the good lord’s name would they change a perfectly good name I have no clue; probably the general population was becoming so familiar with this disease that our researchers needed to change it just to confuse you all.

Over 10% of all cats admitted to veterinary hospitals suffered from FLUTD. Most symptoms relate to the inflammation produced in the urinary tract and include: increased frequency of urination, prolonged squatting or straining while urinating, urinating in unusual places, a painful abdomen when touched or lifted, and bloody urine. Additionally
your kitty may stop eating, vomit, and act very lethargic.

FLUTD can be a life threatening problem for cats, especially male cats who become obstructed and cannot urinate. Kidney failure, electrolyte imbalances, and death can result. The cause of FLUTD is unknown; some of the more popular theories include mycoplama, viruses, dietary/nutritional, inflammatory diseases, autoimmune disease, and infrequently, bacterial. Struvite crystals (composed of the minerals magnesium and phosphorous) were so commonly associated with the disease that most cat foods now limit their presence. Many foods also are formulated to maintain an acidic ph which prevents the crystals from forming. So why has the disease not gone down in prevalence?

In our practice we are seeing some cats developing oxalate crystals, which are crystallized in acidic urine. We also have a number of cats who routinely “block” without having any crystals (either struvite or oxalate). These cats fall under the heading of amorphous matrix plugs. This just shows that researches are somewhat baffled by this disease.

If your cat has FLUTD your veterinarian will try to find a cause and may order some of the following tests: complete blood cell counts, urinalysis and urine culture, blood chemistries, and abdominal radiographs. Treatment entails correcting the dehydration and electrolyte imbalances with intravenous fluids and relieving urethral obstruction with a urinary catheter. Cats are usually placed on antibiotics even though the vast majority of cats have sterile urine (ie. no bacteria); we don’t know why they work but most of us are afraid to treat cats without using antibiotics, especially if a urinary catheter is placed. A urinary catheter increases the opportunity for bacteria to gain entry in the bladder so it is best to leave it in place as short a time as possible.

A problem that male cats have after being obstructed is damage to the bladder detrusor muscle. A good analogy for this is a pair of panty-hose that has been stretched out and loses it’s elasticity. If the bladder is distended too long the muscles get stretched and cannot contract the bladder to void the urine. To help the kitties we make sure their bladders stay small, either through manual expression of the bladder, palpating the bladder throughout the day, or by keeping the urinary catheter in place for a long time. Drugs such as diazepam or phenoxybenzamine are also used to help. Finally, a dietary change may or may not be recommended by your veterinarian; this depends on what you are feeding now and what info we glean from the urinalysis and radiographs.

Whatever you call this insidious disease, FLUTD or FUS, it is a serious problem for cats and a life threatening problem for male cats. Occasionally a drastic surgery called a
perineal urethrosotmy is needed where the penis is amputated in order to make an opening for the cat to urinate. Clearly it would be great for our feline friends if we could eliminate this disease!