Feline Urinary Tract Disease

 

A serious problem in cats, especially males, is called Feline Lower Urinary Tract Disease. It is sometimes also called by its previous name, Feline Urologic Syndrome (FUS). It is a disease of the urinary tract that is sometimes related to the buildup of crystals, leading to inflammation of the lining of the urinary bladder and urethra. In many cases there is no crystal buildup, so dietary changes will be unhelpful.

We have a page on bladder stones that should be read in conjunction with this page.

Graphic pictures are also present on this page as we demonstrate one of the treatments for this problem- you will be notfied when they are appearing.


 

Cause

The crystals that form in the bladder and urethra are caused by many factors, many of which are poorly understood. They include diet, urinary tract infections, and others we are not aware of. Fortunately, the dietary factors and infections can be controlled and even prevented. In a significant number of cases no cause can be determined. The name of the disease in this case is called idiopathic FLUTD. Idiopathic means that a cause cannot be identified at this time.

Two of the more common minerals that cause these crystals are struvite and calcium oxalate. Struvite is a combination of 3 minerals; magnesium, ammonium, and phosphorous. We tend to encounter this mineral combination in young adult cats. They are usually treated with diets to decrease the pH of the urine.

Calcium oxalate is the other common mineral. It tends to occur more in older cats. They are usually treated with surgical removal when found in the urinary bladder.

Diet

One of the predisposing factors in FLUTD is the magnesium (ash) content of the diet. It used to be thought that diets low in magnesium are particularly helpful in preventing the struvite crystal problem. This is not true in most cases, it is the change in urine pH from alkaline to acidic that prevents struvite crystals. In spite of this, many cat foods have restricted magnesium. Unfortunately, this diet can predispose to calcium oxalate crystals. After many years of treating cats with this low ash food we are starting to see an increase in calcium oxalate crystals for this reason. This is another example of how subtle changes in physiolgy, that make sense at first glance and are used successfully for many years, can have untold manisfestations later.

Urine pH

It has been found that the the higher the pH (the more alkaline) the greater is the tendency for struvite crystals to form. High quality cats foods help keep the pH in the acidic range, helping to prevent struvite crystals from building up. Unfortunately, this acidic (low pH) urine now predisposes cats to calcium oxalate crystals. As a matter of fact, we are starting to see these crystals more commonly than struvite. They also tend to form with excess use of cortisone. It is important to know the pH of the urine to determine the best way to prevent buildup of crystals. For an accurate determination, the pH of your cat’s urine needs to be measured immediately when removed from the bladder. Getting a urine sample at home, and checking the pH later is not an accurate indicator of the true pH of the urine.

Infection

Urinary tract infections might predispose cats to getting this disease, although it is difficult to prove this. Even though it is rare to culture bacteria from the urine in these cats, they do respond to antibiotics. Yet many of these cats get better without antibiotics. Viruses are implicated as a cause of this disease also.

This is typical of a urine culture from these cats. After 48 hours of trying to grow a bacteria from the urine sample there was no growth.

The MIC stand for Minimum Inhibitory Concentration-this is the amount of antibiotic needed to kill this bacteria, if a bacteria had been culture out.

Cysto is an abbreviation for cystocentensis, the manner in which we obtain the urine from the urinary bladder.


 

Symptoms

Urine pH

Cats with the non obstructed form of this disease will typically be straining to urinate (stranguria), have blood in the urine (hematuria), or producing small amounts of frequent urine (pollakiuria). These symptoms can be subtle and easily missed, especially in cats that urinate outside. It is easy to confuse these symptoms with a cat that is constipated. In the male cat this problem can progress to the obstructed form of the disease, which is a medical emergency.

Other symptoms might include poor appetite, uncomfortable or in pain when petted or picked up, or lethargy.

Obstructed Form

When the quantity of crystals progresses to the point that a plug is formed then a cat becomes obstructed. This amorphous plug is not the same thing as a bladder stone. In most cats the plug that forms is made up of struvite crystals.

Cats without crystals in their urine can also get the obstructed form of the disease. This form of the disease is seen almost exclusively in male cats due to the substantially smaller diameter of their urethra. There will be repeated trips to the litter pan with straining, and crying in pain upon attempting to urinate. Again, these symptoms can be confused with constipation. Sometimes a few drops of bloody urine are produced, although many cats cannot urinate at all.

As the problem progresses these cats start vomiting, become depressed and dehydrated, and stop eating. as the problem progresses over several more hours the kidneys are unable to function and dangerously high levels of phosphorous and potassium build up in the blood stream. If not corrected, the affected cat will die from a buildup of toxins or cardiac arrest due to the high potassium.

Since all these symptoms are variable and can be quite subtle, the important point to remember is to observe your cats urinary habits on a daily basis and have your pet checked if there is any change to these habits. The symptoms of FLUTD can mimic other diseases, so an accurate diagnosis is imperative.


 

Diagnosis

A thorough history and physical exam go a long way towards making this diagnosis. Urine samples,blood samples, and even x-rays are used in some cases to verify the diagnosis and eliminate other diseases that can cause similar symptoms. Urine samples can be hard to obtain because these cats urinate as soon as urine fills the bladder due to the inflammation caused by the crystals. The FeLV andFIV status of all cats should be known, so these tests might be included also.

This is a picture of a cat’s abdomen. It is laying on its right side and its head is towards the left. The large, round and whitish area towards the right is the urinary bladder (B) that is distended because it cannot urinate. Compare it to the normal sized bladder below.


 

The normal sized bladder (B) in this cat is much smaller. In addition you can see the Large Intestines (L.I.) and the kidney (K). The small intestines (S.I.) are all the round and whitish objects at the bottom of the abdomen below the large intestines.

 


 

Urine samples can be useful. This one shows that there is blood in the urine an no bacteria are noted. This is typical of FLUTD.


 

Treatment Diagnosis

Unobstructed Form

Many cats will get better without any therapy at all, usually within 7 days.

For years these cats were treated with a food that acidified the urine. This food has been the gold standard for treating cats with this problem, and has helped many cats get over this disease. This acidification can be harmful though, especially in a cat withkidneydisease. It can also predispose at cat to getting calcium oxalate bladder stones.

The use of antibiotics in general is not recommended because bacteria are rarely cultured in the urine in younger cats. Indiscriminate use of antibiotics in these young cats can cause the appearance of resistant bacteria. Older cats will get a urinary tract infection due to bacteria . This infection might be related to several disease syndromes, especially sugar diabetesfeline hyperthyroidism, and kidney disease.

Other medicines include cortisone to decrease inflammation and tranquilizers and antispasmodics to minimize muscle spams of the bladder and urethra. None of these medications have been definitely proven to limit the course of the disease. In addition, they all have the potential to cause side effects. Their use might be indicated as long as they do not cause more harm then good.

Oftentimes we give fluids to help flush out the urinary tract and maintain a proper state of hydration. This is a great way to help these cats, especially since there is negligible chance of problems, and we are treating them in a natural way without the use of drugs.

For cats with struvite crystals Hills c/d Multicare is the food to feed.


 

obstructed Form

If not detected early and observed carefully, the unobstructed disease can rapidly progress to a full obstruction of the urinary tract, especially in males. This causes acute renal failure, and will lead to death if left untreated.

These cats need emergency intravenous (IV) fluids and a urinary catheter placed in the urethra. These pets also need anesthesia for us to be able to pass the urinary catheter into the urethra and start the flow of urine again.

The following graphic pictures show such treatment.

An intravenous catheter is placed in the cephalic vein located in the front leg. It is thoroughly wrapped and will be a crucial part of the treatment. These fluids will minimize the anesthetic risk to kidneys that are already severely compromised and will also allow the flushing of the crystals out of the bladder. These fluids will rehydrate a dehydrated cat, and also flush out excess potassium which can cause serious problems and even death.

 


When the fluids are running and the patient is properly sedated, an attempt is made to remove the urethral plug. In some cats gentle massage of the urethra accomplishes this task. In most cases, a sterile small gauge IV catheter or lacrimal canula is used to gently flush out the crystals that are lodged in the urethra. This part of the procedure can take the most time because the flushing has to be gentle, yet the crystals can be almost solid in nature.


 

When the plug is completely flushed out of the urethra the urine will immediately flow from the distended bladder. Often times it has blood in it. In this picture the urine stream is going from the urethra on the left into the bowl on the right.

 


 

When almost all of the urine has flowed out of the bladder a special male urinary catheter is placed in the urethra and sutured into place. It will stay in from 1-3 days in most cases. Some cats do not need this catheter if their obstruction was minor and they have an adequate urine flow after their obstruction is removed.


 

The urinary catheter will be hooked up to a collection bag to monitor urine output. Keeping the catheter in the urethra will let the distended bladder rest so the injured muscles can return to normal function faster.


 

Here is our patient waking up from anesthesia with catheters in his vein and his urethra. Even though these catheters can be uncomfortable, just relieving the pressure on the bladder and allowing the kidneys to function properly again are a tremendous source of relief.

 


Most cats respond rapidly to treatment and can have their urinary catheters removed 24-48 hours later. They will remain in the hospital and be closely monitored for urinary output. On occasion they can re-block and need to have their urinary catheter replaced.

Cats that have had their bladders distended significantly before they were unblocked can have a difficult time urinating after they are unblocked. Urination is painful and the muscles that contract the bladder do not function well initially. The cats will be put on medication to minimize straining and our nursing staff will gently express the urine from their bladders when it starts to build up. If they don’t eat well we will assist feedthem. Most of these cats do well and go home in a few days. Sometimes we need owners to express the bladders at home also.

As a general rule cats with struvite crystals should be fed Prescription Diet S/D for 30 days to help dissolve crystals that remain in the urinary bladder. Then they are switched to Prescription Diet C/D or Science Diet Feline Maintenance on a long term basis.


 

Surgical Treatment

Some cats re-block continually in spite of prevention measures. Also, some cats are so severely blocked the first time that it is impossible to flush the crystals out of the urethra and place a urinary catheter to allow the flow of urine again. These cats need a surgery called a perineal urethrostomy, which in essence is a partial amputation of the penis. The penis is amputated far enough back to the point that the urethral opening is larger and there is minimal chance that a plug can accumulate and cause a blockage.


 

Prevention

Keeping your cat active and in good health goes a long way to preventing this problem, especially if it is obese. Keeping the litter pan clean and giving your cat access to fresh water at all times will also be helpful in prevention. The most important thing you can do is to make sure your cat is drinking adequately. The diuretic effect of adequate hydration goes a long way towards preventing this disease. If need be, give your cat supplemental water with a syringe or feed a canned food.

Cats in general maintain an acidic urine. a normal response to eating is to produce an alkaline urine initially. Medically this is called post-prandial alkalosis. If struvite crystals are implicated, this alkalosis will add to the problem. To minimize post-prandial alkalosis keep food out at all times (called ad libitum feeding).

Feeding the proper food, especially if crystals are implicated as a cause, is also an important preventive measure.

Cats that have had an episode of FLUTD should be examined by one of our doctors and have a urinalysis performed at least every 6 months.