Ronald S. Hines DVM PhD

This problem is called Feline Urological Syndrome (FUS), Feline Lower Urinary Tract Disease (FLUTD) or FUS/FLUTD. It is responsible for 5-10% of the office visits that bring cats to veterinarians. Owners often present the cat for a "litter box problem" - either too much time spent in the box or urination outside of the box.

Male and female cats both get this problem; but it is only a life-threatening disease in male cats.

FUS is a perplexing disease of the bladder and urethra. We do not understand why one cat develops this problem while another cat under the same circumstances does not.

In FUS/FLUTD, sharp crystals fall out of solution in your cat's urine while it is still in the bladder. They irritate the lining of the lower urinary tract and may mix with debris to prevent your cat from urinating.

What Kinds Of Cats Get This Problem?

Cats of any age can develop lower urinary tract problems. But the average cat is about 4 years old when signs begin. It is highly uncommon in cats under 1.5 years of age. Old cats can also develop FLUTD. But when they do, they usually have another, underlying problem. We see FLUTD a bit more frequently in Persian cats than in standard domestic cats.

Until the mid 1990s, these crystals were usually composed of the mineral, struvite (ammonium-magnesium-phosphate). But since then, the incidence of calcium oxalate crystals has mysteriously increased until currently, they make up more than half the cases of FLUTD. The presence of these crystals is never fatal to female cats but it is life-threatening in male cats if it prevents their urination. I think of this disease the Garfield syndrome – because it appears to be a disease of easy living. It is usually a pampered indoor cat that develops the disease.

Much more about FLUTD still remains unknown than known.

What Signs Will I See In My Cat?

The first thing many owners notice is that their cat is spending too much time in it's litter box. A second common complain is that their pet is urinating outside the litter box.

It will be hard to know if the cat is attempting to urinate or poop. But they squat too long. Sometimes they will meow while trying. Between attempts, they lick there genital area. There may be blood in the urine. Their penis may no longer be withdrawn entirely into its sheath and it may be bluish or inflamed on its tip. There may be a white, cheese-like material surrounding the penis and sheath.

These pets often begin to urine spray in unusual locations in the house.

Why Is This Happening To My Cat?

When FLUTD/FUS occurs, small sharp crystals form in the pet's urine, irritating the bladder and urethra lining. Sometimes , actual gravel-like stones form.

Because struvite crystals contain magnesium, one theory was that the problem occurred due to feeding cat foods high in mineral (ash). This seemed logical. The only problem was that no one was able to reproduce the disease by feeding high ash/magnesium diets. Some contributors to pet food ash are necessary (calcium and trace minerals) - however, cheap cat food is often higher in ash than it should be.

So other factors must be at work. Some speculated that a bacteria or virus are involved. However, most cats with this problem have no bacteria or virus in their urinary tracts.

Another thought was that lethargic, indoor cats do not drink enough water. We know that these crystals occur more frequently in concentrated urine. However, just as we could not cause the disease with high ash diets, producing concentrated urine didn't cause the disease either.

Struvite appears when the pH (acidity) of your cat's urine is greater than 7 and when dietary magnesium levels are high. When animal nutritionists realized this, they reformulated cat foods to produce acid urine with a pH range of 6.3 to 6.7. This reformulation did lower the incidence of struvite crystals in house cats. However, it apparently increased the number of cats that formed calcium oxalate crystals. So today, oxalate crystal problems outnumber struvite problems.

Why Is The Problem Much Worse In Male Cats?

Male cats have narrower, longer urethras (the tube leading from the bladder to the outside). If this tube gets blocked, the cat can not urinate and becomes extremely ill.

Female cats with the same problem are in distress due to the pain, but because the urethra is shorter and wider, they never loose the ability to urinate.

Is This A Medical Emergency?

It is a medical emergency when your male cat can not urinate. Urination is how the body cleanses itself of toxic waste products. Urination is also critical for the cat to keep the proper balance of minerals and water in its body. It doesn't take long (24hrs) for cats that can not urinate to become depressed and for systems in their body to begin to fail. If you suspect blockage in your male cat during the day, take it to your veterinarian immediately. If their office is closed, take it to a 24 hr emergency veterinary center.

When urine backs up into the kidneys, the pressure within the kidneys goes up. This will cause irreversible kidney damage if the pressure is not relieved. Two to three days in this condition is fatal.

You can confirm that your cat is blocked if you feel a hard lemon-size "ball" in the lower rear abdomen. The cat will cry when you attempt to feel it. Do not squeeze firmly. Even if you feel nothing, bring the cat to a veterinarian to have it checked there as well.

Experienced veterinarians can identify the male cats with FLUTD that are at most risk for blockage. When the bladders of these cats are expressed, the stream of urine is very narrow. This is due to swelling an inflammation of the urethra.

How Will You Restore My Cat's Ability To Urinate?

We try to break down the blockage in the least traumatic way possible. Trauma to the urethra causes it to swell - then the likely hood or the cat blocking again becomes greater.

The plug that blocks male cats is composed of mineral crystals and cellular debris. It has the consistency of cottage cheese. In many male cats, this plug is only near the tip of the penis. In these cats, gentle massage of the penis often breaks down the plug and allows the cat to urinate. This is the first method that should be tried.

If gentle pressure on the bladder and massage of the penis is not sufficient, many veterinarians use a small, soft catheter to "jet" a stream of saline around the plugs and flush them out. This is called retropropulsion.

If that is still unsuccessful, the veterinarian will have to catheterize the cat. Using the retropropulsion technique, a very small, soft catheter is slowly advanced into your cat's bladder. Sometimes the bladder has been over-distended so long that the urine must be removed through the catheter with a syringe. The color and consistency of the urine is a good indication as to how long the cat was blocked and how much damage has occurred.

Pets that are still fully conscious often need to be sedated or anesthetized to pass a catheter into their bladder. In the sickest animals, it can be done without these drugs. Once the blockage is removed, the pet will be given intravenous fluids and buffers to correct electrolyte (salts) imbalances, flush out its kidneys and encourage urination. Once that is done, the cat's kidney function needs to be tested to see what damage, if any was done.

Most cats will pull their catheter out if they do not wear a sunflower-like collar. They need to stay at the animal hospital until the staff is pretty sure the pet will not plug again. It is also important that their kidney function, and water consumption return to normal before they leave. They may also receive antibiotics and medications to relieve pain and help relax the urethra. If the cat is to be sent home before this , I have the owners bring the pet in twice a day to be sure the bladder is emptying and it is doing well.

What Medical Treatment Will My Cat Need?

Pain Control:

This is a painful condition for your cat. A pain control medication called butorphanol or buprenorphine can help with this. Other veterinarians use Non-steroidal anti-inflammatory agents such as Metacam for the same purpose.

Antispasmodics:

These are drugs to relax the urethra and bladder wall. When these areas are inflamed, they go into spasm, causing pain and making obstruction more likely. So it would seem that medications to minimize this would be helpful. Two that are commonly used are propantheline and oxybutynin. However, some veterinarians feel they do more harm than good and use diazepam (Valium) for much the same effect.

Antibiotics:

In most cases these are probably unnecessary. But they are still commonly dispensed to cats that have had a FLUTD episode. Bacteria use urinary catheters to move up into the bladder and kidneys. So protecting the pet from this with antibiotics may be wise.

Increased Water Consumption:

The more water your cat consumes, the more dilute its urine will be and the less likely it will be that crystals form. So encouraging your cat to drink is important to cure it of its current problem and to prevent future relapses. Heavy urine production also helps flush crystals and debris out of the urinary tract. Cats are not big drinkers. But changing their diet to canned food will supply them with more water. You can add a meat broth to the canned food to supply even more water. Be sure one or more water bowls remain full. Try putting them in novel containers, fountains and locations to increase the pets curiosity. Some veterinarians suggest distilled water. There is no harm in giving distilled water - but ordinary, tap water that meets EPA standards is fine.

Reduce Stress In Your Cat's Life:

Cats are creatures of habit. They often break with FUS/FLUTD during periods of stress. This is often a move, the introduction of another cat or a diet change. Try to return the situation to what it was before the problem occurred. If you can not, be sure your cat has some private space to itself. Some owners find pheromone products like Feliway or catnip helpful. If you have a multi-cat household, the problem is more difficult. Some cats just don't like the company of other cats. Do what you can to give each of them their own, separate space, food, food and water bowels, and litter box.

Some veterinarians dispense amitriptyline, an anti-anxiety medication to try to help anxious cats. Other tranquilizers may also be helpful. Another medication with a similar effect is clomipramine. The effectiveness of either medication in decreasing FLUTD attacks is still unknown.

Glucosamine Supplements:

Glucosamine and chondrotin have been recommended for cats with this problem. They are building blocks of the protective glycosaminoglycan coating of the bladder. Pentosan polysulfate which is marketed for relief of interstitial cystitis in humans and Adequan, used for arthritis in pets, have also been used. There is no harm in giving them.

Urinary Acidifiers For Struvite Crystals:

Struvite crystals dissolve when the cat's urine is acidified. However, it is much more effective if this is accomplish using a commercial diet that is designed to produce an acid urine than by giving urinary acidifiers. If your cat is in the middle of an FLUTD crisis, feed a diet furnished by your veterinarian. If the problem is mild or the cat's urination appears normal, you can try a non-prescription diet formulated for lower urinary tract health (such as Purina Special Care Formula).

Potassium citrate For Oxalate Crystals:

This compound has been shown to raise the pH (lower the acidity) of urine. Oxalate crystals only form in acid urine - so reducing the acidity should help prevent them. Potassium citrate will not dissolve crystals or stones that have already formed. If these can not pass, they will have to be removed from your cat surgically.

Would Surgery Help?

A few cats with FLUTD will have actual granules of mineralized material plugging up their urethra and bladder. In these animals, the bladder must be opened and the material removed. This surgery is called cystotomy.

But in the majority of cats, the material is fine and pasty. When cats with this more common form relapse despite everything you do, the best solution may be a surgical procedure called a perineal urethrostomy.

This surgery works best in male cats that have a very narrow portion of urethra near the tip of their penis. In these cases, plastic surgery restructures that portion to prevent debris and crystals from blocking. It does not prevent the crystals and debris from forming. When the surgery is complete, your cat will look allot like a female cat.

This surgery can be the only way to save the life of your cat if diet, medication and life style changes do not control FLUTD. However, it is not always successful. Also, cats that have had this procedure are also more prone to bacterial infections gaining access to their urinary system. So they need to be monitored throughout their lives for urinary tract infections.

.What Causes FLUTD?

The short answer is that we do not know. We do know that overweight cats, cats consuming dry cat food, cats that do not drink adequately and cats in multi-cat households are more at risk. But we see FLUTD is cats that do not fit in that group. In those cats, veterinarians think that perhaps genetics, and even the age at which they were neutered might be factors.

Occasionally, an underlying cause is found. But in the majority of cases, no underlying cause is found.

In the cases where struvite is the problem, anything that causes the urine to be less acidic or more concentrated is thought to make the problem more likely to occur.

In the case where oxalate is the problem, too acid a diet and insufficient water consumption are probably involved. Genetic factors probably also play a part because Burmese and Himalayan cats have more than their share of oxalate problems. On the average, oxalate problems develop in cats at a bit older age than struvite. Thirty-five percent of the cats with oxalate problems have blood calcium levels that are too high.

Will The Problem Reoccur?

We currently have no way to predict that. Some cats have only one incident of FLUTD in their live. Others have repeated episodes despite all we do to prevent them. Until we understand the causes better, we can only give general suggestions.

Here is some advice that is thought to help:

What Kind Of Diet Changes Would Help?

If The Problem Is Struvite:

Veterinarians sell many brands of diet that are formulated to help prevent struvite FLUTD. These diets do this by promoting acidic urine. I would prefer your feed cats with FLUTD a canned diet. However, you will need to be sure your cat does not put on excess weight.

It is also important that your cat munches throughout the day, as cats like to do. By eating small amounts frequently, your cat will minimize the tendency to have alkaline urine (high pH) shortly after a large meal.

No mater what you feed your cat with a struvite crystal problem, it is important that you keep track of its urine pH. It should stay below 6.5 most of the day.

If The Problem is Oxalate:

If your cat was found to be hypercalemic (too much blood calcium) the cause needs to be looked into.

If your pet's blood calcium level is normal, veterinarians also sell many brands of diet that are formulated to help prevent oxalate formation. These diets are high in fiber and have only the amount of protein required by cats. They promote a urine pH that is not in the range where oxalate crystals are likely to form.

It appears that having specific meal times for your cat rather than food available at all times, also helps keep the pet's urine pH closer to neutral.

Do not allow your cat to consume Vitamin C supplements.

You can collect a few drops of your cat's urine by placing a sheet of clear plastic film over the litter or purchasing special litter designed for that purpose. If you can, monitor your pet's urine pH and specific gravity. You can purchase strips that record the pet's urine pH and purchase a small device called a refractometer to measure urine specific gravity. Cats are most likely to do well if their urine pH remains between 6.8 and 7.0 and if the specific gravity of their urine remains between 1.020 - 1.025.

Bring a urine sample in to your veterinarian occasionally to be checked for the presence of distinctively shaped oxalate crystals. It is normal for there to be a few struvite crystals in the urine.

If oxalate crystals are still present, the cat should receive a potassium citrate supplement. Some veterinarians also suggest a vitamin B-6 supplement.