Any male cat having any degree of trouble urinating should be examined immediately.
This condition constitutes a true urologic
emergency



Feline Lower Urinary Tract Disease


Chris C. Pinney, DVM

In the normal, day-to-day functioning of the body, much waste material is formed as a result of metabolic activity. It is the function of the urinary system to handle and to rid the body of these waste products. In addition, through its ability to dilute or concentrate the urine, it serves to regulate fluid levels within the body.

Because of its vital function, any interference or alteration of urinary system function can quickly have serious health consequences. For this reason, prompt and proper diagnosis of urinary tract disorders in cats is essential. Periodic checkups by a veterinarian can help detect potential problems before they reach such a magnitude as to threaten the life of a cat.

Feline lower urinary tract disease (FLUTD) [known in the past as feline urologic syndrome or (FUS)], is a disease syndrome of cats characterized by the formation of crystals (most commonly struvite crystals) within the urinary bladder. These crystals, in turn, cause inflammation, urinary bleeding and straining, and sometimes life-threatening obstruction to the normal flow of urine out of the bladder

No one knows for sure why some cats get FLUTD and others don't. Many potential causes have been hypothesized, including viruses, abnormal urinary retention, obesity, bladder defects, and-the most popular theory to date is improper diet. In reality, one or all of these factors might play a role in the occurrence of FLUTD.

Blocked Cat - Urethral Obstruction

Lower urinary tract disease in male cats can lead to an obstruction that damages the urethra, bladder and kidneys.  The above illustration shows a life-threatening obstruction of the male penile urethra.

If a cat is prone to this disorder, it will usually show some signs of the disease when it reaches 3 years of age, although urinary tract blockage can occur at almost any age. Both male and female cats are at risk of developing FLUTD; however, males have a greater likelihood of developing a life-threatening obstruction simply because the male urethra is smaller in size than that of the female and can become plugged with crystals more easily. If such an obstruction occurs, urine can back flow back into the kidneys resulting in death from acute renal failure and/or severe damage to urinary bladder.  At the very least, toxins can  build up in the bloodstream leading to serious systemic illness.

Early clinical signs of FLUTD result from the irritation that these crystals cause within the bladder itself.  These can include inappropriate urination in places other than the litter box or normal elimination areas, increased licking at the genital region, straining, and frequent attempts at urination with crying or vocalization, and blood in the urine. Cats often lose their appetites and become more irritable as well.  More seriously, male cats suffering from partial or complete obstruction of the urethra can exhibit vomiting, intense lethargy, and a distended, painful abdomen.

Diagnosis of FLUTD is based on clinical signs, physical examination, and a urinalysis. An enlarged, painful bladder can also be palpated in those cats suffering from some degree of obstruction.  If a bladder infection is suspected, then urine cultures might also be performed.

The obstructed cat will usually have high levels of kidney enzymes [blood urea nitrogen (BUN), creatinine] present in its bloodstream, signifying the toxin buildup and kidney destruction that is occurring. Most veterinary hospitals are equipped to monitor these enzymes.

If an actual obstruction is suspected, then rapid treatment is essential to save the life of the cat. Obstructed cats are immediately placed on intravenous fluids to help dilute the toxin levels within the bloodstream. A catheter is then inserted into the urethra to "unplug" it in order to reestablish urine flow. Once this flow is reestablished, the bladder is flushed repeatedly with sterile saline to remove any crystals that might be remaining within.

It is up to the veterinarian's discretion as to whether to keep the urinary catheter in place for a few days. While catheterized, these cats are placed on antibiotics to prevent any secondary bladder infections from occurring as a result of catheterization. Intravenous fluids are continued in the hospital setting for 2 to 3 days after the obstruction is relieved.

For the cats that are not obstructed but are still showing signs of FLUTD, smooth muscle relaxants and anti-inflammatory medications can be used to help reduce the discomfort and urge associated with this disease. The use of antibiotics in such patients is still controversial; studies have shown that bacterial infections are present in less than 20 percent of the cases. However, if urine culture confirms the presence of such, antibiotics are, of course, indicated.

Altering the pH of the urine in order to dissolve any crystals present within the bladder is another important step in treating this disease in both obstructed and unobstructed felines. Struvite crystal formation in cats with FLUTD is promored by an alkaline urine pH.  Rendering the urine more acidic will help dissolve existing crystals and help prevent the formation of new ones. On the contrary, promoting a more alkaline urinary pH will help manage oxalate crystals within the bladder. As one can see, it is vital that crystals be properly identified during the diagnostic process. 

Most veterinary researchers agree that diet plays the foremost role in the creation and in the treatment and prevention of this disease syndrome. Dry diets are the major culprits in promoting FLUTD in cats as well as feeding patterns. 

Unfortunately, many of the commercial supermarket brands of cat food contain excesses in mineral content and/or do not promote a balanced urine pH.  Diets specially formulated for the prevention of FLUTD can be obtained in both moist and dry forms from most veterinary offices. Although a dry diet similarly formulated should inhibit struvite formation, clinical studies have found dry foods to be less efficacious than canned foods. Benefits of increased water intake could include dilution of any noxious substances in urine, more frequent urination to decrease bladder contact time with urine, and removal of any excess crystals. Because of its high calcium and mineral content, cow's milk should never be offered to those individuals prone to FLUTD.

Besides feeding a canned diet that acidifies the urine, providing cats free access to a fresh water supply is a must. Increased water consumption will help increase the number of urinations each day, effectively keeping the bladder flushed out. In fact, most commercial diets formulated for the, prevention of FLUTD have an increased salt content to promote increased water consumption. With these increased urinations comes the responsibility of cleaning the litterbox on a regular basis. Many cats refuse to urinate in a dirty litterbox, a practice that encourages urine retention and FLUTD.

Although it might not seem important, regulating the frequency of meals fed can play a direct role in the prevention of FLUTD. After a cat consumes a meal, its urine undergoes a temporary rise in pH (postprandial alkaline tide). For those cats allowed to eat and nibble all day long (such as those fed dry foods), this might promote relatively constant alkaline urine, and thereby predispose to struvite crystal formation. As a result, in terms of preventing FLUTD, offering one or two meals a day rather than free-choice meals is preferred.

Obese cats are more prone to FLUTD than are their slimmer counterparts, so weight control is an important preventive measure to follow as well. Overweight felines, especially those who have exhibited signs of FLUTD in the past, should be placed on reducing diets prescribed by their veterinarians, and their activity levels should be increased until the desired weight is reached. Once weight loss is accomplished, they can be switched back over to preventive-type rations.

Without proper dietary management, FLUTD can be expected to recur over 50 percent of the time. In some cats, however, FLUTD  recurs over and over again, even with dietary management. In these instances, treating the symptoms when they first appear and continuing with prevention measures will usually keep such episodes from turning serious.

For those male cats with a history of recurring obstruction, a special operation known av. perineal urethrostomy might be indicated to reduce the danger of death due to urinary blockage. This surgery involves removal of the end of the penis and widening the urethral opening, effectively allowing for free passage out of any and all crystals. Keep in mind that such a procedure is not intended to cure the FLUTD; it merely lessens the risk of severe, life-threatening complications associated with it.

 

Prevention and Home Monitoring            

Home monitoring of urine pH and for the presence of blood may be performed with urine dipsticks after urine has been collected from the litter box. This may be accomplished by replacing the normal litter with Non-Absorbable Cat Litter (Veterinary Concepts, Inc., Spring Valley, WI), aquarium gravel, or the perforated strips from computer paper, or by using the Uro-Collect Feline Kit (Jorgensen Laboratories, Loveland, CO). These do not absorb urine; therefore the test strip can be dipped into the urine while it is still in the litter pan. other alternatives include material that is added to normal litter and reacts to the presence of an alkaline pH or blood (CatScan pH and CatScan B, Health-Check, Buford, GA) and pH-indicating cat litter.

 

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