FLUTD: Feline Lower Urinary Tract Disease

Feline Lower Urinary Tract Disease (FLUTD) is a class of diseases with multiple causes that can profoundly threaten your cat’s health. There are a variety of different conditions described by the term FLUTD- but each is united by its localization to the urinary tract.

The urinary tract, or renal system, refers to the organs that eliminate waste from the body and regulate the pressure, volume, composition, pH, and electrolyte and metabolite concentrations of the blood. This system consists of the urethra, bladder, ureters, and kidneys. Though the lower urinary tract generally refers to the bladder and urethra, FLUTD may involve any of the organs in the renal system.

FLUTD affects your cat’s ability to eliminate waste properly, which is an essential function in any mammal. If left untreated, these diseases can be fatal- so it is essential to identify and treat these disorders as quickly as possible. Because FLUTD affects between 1–3% of cats annually and recurs in 50-70% of cases, we here at EntirelyPets have compiled this information to help you understand and treat this affliction (“Feline idiopathic cystitis (FIC)”, n.d.).

Preventing FLUTD

Most instances of FLUTD can be prevented with routine care for your cat, specifically by feeding your cat only properly formulated wet food. Though some cats may be predisposed to particular afflictions within the scope of the disease, many cats that suffer from FLUTD do so due to environmental stress. Other cats that suffer from rarer instances of this disease can avoid serious complications through specialized routine care.

The standard care that should be provided to any cat to prevent FLUTD diseases includes feeding small meals on a frequent basis as part of a regular daily schedule, ensuring that fresh and clean water is available at all times, and providing an adequate number of clean litter boxes in safe and quiet areas. These concerns should be observed by all cat owners, but are particularly important for cats that are male and neutered, and cats that are between the ages of 2 and 5 years old (Buffington, Markwell & Smith, 2015).

The ideal diet for a cat to prevent FLUTD is sensitive to their needs as obligate carnivores and their tendency toward dehydration. Wet diets that are low in carbohydrates and high in animal protein are recommended. Certain compounds called glucosaminoglycans (GAGs) can also greatly benefit your cat’s bladder health.

GAGs are used by your pet’s liver to create a mucosal lining that protects the bladder wall from acidic urine. Therefore, diets that contain highly bioavailable GAGs can prevent damage to your cat’s bladder and have also been shown to aid in the dissolution of urinary stones ("Feline lower urinary tract disorder (FLUTD)", n.d.). Another factor to consider when examining the composition of your cat’s diet is the pH of your cat’s food.

Though the formation of certain uroliths, or urinary stones, is tied to dietary magnesium and phosphorus levels, the pH of your cat’s food plays a much more significant factor in urolithiasis. Most experts suggest a diet with a pH between 5.9 and 6.3. This figure, however, may change once urinary stones have formed. Some treatments may aim to increase urine acidity to dissolve the obstruction, while others may require less acidic diets depending on the composition of the obstruction (Buffington et al., 2015).

Additionally, dietary ingredients rich in water-soluble constituents have been shown to provide relief from urinary incontinence. Studies in both humans and rats show that pumpkin seeds reduce instances of urinary incontinence by strengthening the pelvic muscles. These seeds contain water-soluble constituents that inhibit aromatase enzymes and facilitate binding to androgen receptors, thus increasing testosterone levels. This increase in testosterone helps strengthen the pelvic muscles, facilitating healthy urination. This may be especially helpful for cats that have been neutered, as these cats typically experience a decrease in testosterone levels, which may weaken pelvic floor and sphincter muscles (Faloon, 2008).

Identifying FLUTD

As FLUTD is actually an assortment of related diseases, the symptoms for each incidence will vary; however, each case of FLUTD is characterized by a unique set of symptoms. These symptoms indicate that there is a problem with your cat’s lower urinary tract and that you should bring him or her to a veterinarian’s office for further diagnosis. They include:

• Difficulty urinating
• Frequent or prolonged urination
• Crying out while urinating
• Excessive licking of the genitals
• Inappropriate marking or elimination
• Bloody urine

Though these signs are universal across the various types of FLUTD, additional symptoms can help narrow down the identity of the specific affliction affecting your pet. Conditions included within the scope of FLUTD can range anywhere from a urinary tract infection to any of several types of cancer. This divergent nature means that it may take several tests before a definite prognosis can be given.

In most cases, the first methods of diagnosis that will be employed by your veterinarian are a physical examination and urinalysis. Following these tests, your veterinarian may run x-rays, ultrasounds, blood work, or bacterial cultures to determine the specific problem affecting your cat. The final results of these examinations will also determine the method of treatment your veterinarian will implement for your pet.

Though there are a large number of diseases that can affect your cat’s urinary tract- each disease can be grouped into one of five classes of conditions: urinary tract infection, urethral obstruction, cancer, anatomical defects, and idiopathic cystitis.

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Approximately two thirds of FLUTD cases have no known underlying cause; these cases are diagnosed as feline idiopathic cystitis (FIC). Most cases of FIC involve issues with the bladder; however, recent research on the topic hints that complex irregularities in the nervous and endocrine systems are also currently included in the scope of FIC. Some cases of FIC have been linked to the gastrointestinal, cardiovascular, respiratory, and immune systems as well (Westropp & Buffington, 2004). Due to the broad scope of this disease, Buffington (2011) considers FIC to be part of a larger class of problems known as Pandora Syndrome.

Symptoms

The principle factors that define cases of FIC are inflammation and diminished defenses in the lower urinary tract. These factors manifest as thickened bladder walls, pain localized to the bladder, and bloody urine. These factors only point to FIC when there is also a lack of any anatomic abnormalities, bacterial infections, or obstructions of the urinary tract, as the term is a broad category for cats suffering from symptoms of FLUTD that do not suffer from one of the four central diseases.

Aside from bloody urination, pain is typically recognizable through urination outside of the litter box and excessive grooming around the afflicted area. Symptoms of this disease typically subside without treatment within five to ten days of their initial onset. Though the symptoms may subside, they are likely to recur at irregular intervals; in severe cases, they may recur more often and persist for longer periods (“Feline idiopathic cystitis (FIC)”, n.d.).

Causes

One common factor among a majority of cases of FIC is stress from environmental factors, with controlled studies showing that more than 70 percent of cats diagnosed with FIC respond positively to placebo treatments. The study also showed that cats can benefit greatly from an enriched environment. Cats with a regular playtime, a stationary litter box, and a regular feeding time experienced a reduction of symptoms by up to 80 percent (Stella, Linda, & Buffington, 2011).

Because these symptoms can be isolated from the other diseases of FLUTD, it stands to reason that these same factors may also worsen cases in which one of the four diseases is actually present. Therefore, even when a cat suffers from infection, cancer, anatomical defects or injury, or urethral blockage or stones- it is recommended to provide the care ascribed to cats with FIC.

Treatment

As stated, many cases of FIC will improve with certain basic changes to a cat’s environment. These changes include ensuring that cats have a safe and large open space, a regular schedule of diet and play, clean litter boxes in convenient locations, and a comfortable social atmosphere both with humans and other cats in the household. Other treatments include using feline facial pheromones to calm distressed cats and drug therapy either to relieve pain or to further reduce stress. According to Becker (2014), calming a cat’s owner can also help relieve a cat’s symptoms.

When improving your cat’s environment, it can be useful to remember that a stable routine is extremely important to cats. Healthy cats will often develop behaviors associated with illness if their routines are altered. In addition to the symptoms of FIC, these behaviors may include vomiting, litter box avoidance and refusal to eat.

While providing consistent meals can aid with the treatment in FIC, certain dietary changes can have an even larger impact on your cat’s urinary health. Providing a diet that is rich in glycosaminoglycans (GAGs) can help improve bladder health, as GAGs compose the mucosal layer that lines the bladder wall. This layer is essential for protecting the bladder from highly acidic urine (“Feline idiopathic cystitis (FIC)”, n.d.).

GAGs are commonly used to treat joint problems, as they also compose the cartilage used to connect joints. Glucosamine, chondroitin, and hyaluronic acid are some GAGs commonly included in pet foods and treats. Finding food formulas and treats that utilize these ingredients can then also provide many benefits to your cat’s urinary tract.

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Symptoms || Causes || Treatment ||

Urinary tract infections (UTIs) are bacterial infections that generally only affect older cats. Microbes can damage the cells of the urinary tract making urination both painful and difficult. An infection may affect any part of the urinary tract from the kidneys to the urethra. Pyelonephritis, or infection of the kidney, can lead to acute and chronic kidney disease- so it is imperative to treat UTIs promptly (Pierson, 2013).

Symptoms of Urinary Tract Infection in Cats

In addition to the aforementioned general FLUTD symptoms, cats suffering from a urinary tract infection may drink a larger amount of water than normal and suffer from incontinence- or an inability to control their urination. If there is a diminished flow of urine- it is likely that there is some obstruction afflicting your cat as well. Cats exhibiting these symptoms demand immediate treatment. To diagnose an infection, your veterinarian will need to analyze a urine sample.

Equally as important as prompt treatment, an accurate confirmation of infection is absolutely necessary. A complete urinalysis is required to confirm a positive diagnosis. This entails more than simple sediment analysis, which is the most common method of urinalysis employed by veterinarians. Procedures known as urine-specific gravity and urine glucose level determination are needed to attain enough data to evaluate a suspected infection (Weese et al., 2011).

According to Weese (2011), an aerobic bacterial culture and susceptibility should also be performed to confirm the presence of an infection. Your veterinarian may also perform blood tests and other examinations to determine if your cat is suffering from any additional disease that may be causing your cat’s symptoms or further complicating your cat’s infection.

Causes

Bacterial infections generally occur when bacteria has traveled up through the cat’s urethra from the cat’s environment. In most cat’s, the acidity of a cat’s urine creates a hostile environment for bacteria that is sufficient to prevent infection. Because of this, in otherwise healthy cats, infections only constitute 1-2% of cases of FLUTD; however, Pierson notes (2011) that diseases that reduce the acidity a cat’s urine, such as chronic kidney disease (CKD), hyperthyroidism, or diabetes, can increase the risk of infection.

Treatment

Because of the rarity of UTIs- when the term is used to refer to infections, as opposed to irritation of the urinary tract- it is imperative that you remain vigilant when seeking treatment. Even in the veterinary field today, it’s not uncommon for antibiotics to be abused when the urinary tract is irritated. In actuality, this treatment should be reserved for cats that have been confirmed to be suffering from an infection or cats that are recovering from surgery (“Urinary Tract Infection in Cats – Causes, Symptoms & Treatment | Cat Health Collection”, 2009).

Most treatments for urinary tract infections aim at relieving the symptoms and discomfort caused by the infection while simultaneously targeting the microbes causing it. A UTI is actually very simple to treat relative to other urinary tract problems; unfortunately, when a urinary tract problem is affecting your cat, there is a very low chance that the problem is actually an infection. Studies show that when a cat is not suffering from an additional health condition such as kidney disease, hyperthyroidism, or diabetes, there is only a 2% chance that discomfort in your cat’s urinary tract is caused by an infection.

While treating an infection, it can be useful to make changes to your cat’s diet and habitat to prevent recurring infections. Regularly cleaning your cat’s litter box may reduce the chance of bacteria accessing your cat’s urinary tract, while a diet that increases urine acidity may create an environment that is inhospitable for bacteria.

In addition to antibiotics and increasing urine acidity, a natural sugar called D-mannose is also known to help fight urinary tract infections in humans and is recommended by Becker (2010) to fight infections in cats. This natural sugar has anitibiotic properties that can help void the urinary tract of bacteria. When included in your cat's diet, the sugar is excreted by the kidneys into the bladder where bacteria attach to it and are then easily and painlessly voided from the bladder.

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One of the most serious cases of FLUTD, urethral obstruction, can put your cat’s life in danger. The severity of your cat’s condition is dependent on how much of the urethra is actually obstructed, the cause of the obstruction, and the cat’s overall health. Male cats are more likely to suffer from this condition because they have a longer, narrower urethra than female cats.

If the urethra is partially obstructed- the symptoms of FLUTD will aptly describe what your cat will experience; however, if the urethra is completely obstructed then the resulting effects will be much more pronounced. The shift can between a partial and a complete obstruction can happen suddenly and is vital to recognize for all cat owners, due to the dangers posed by a complete obstruction.

In cases of total obstruction, the material blocking the urethra makes it impossible for the kidneys to filter toxins from the blood. In this case, it is essential to seek emergency medical treatment for your cat as soon as possible- as the resulting imbalances can cause death within two days. Generally, when a full obstruction occurs, cats will exhibit more signs of pain that reveal the severity of their condition through audible cries.

The method of treating urinary obstruction varies depending on the type of material blocking the urethra. In many cases, the obstruction is composed of minerals that have formed hard stones or soft plugs in your cat’s urinary tract. These obstructions can be caused by many different minerals accumulating; depending on their composition, they can be treated in a variety of different ways. According to Brown (2013), the composition of the most common obstructions are listed below:

Of these crystals, the three most common crystals to contribute to an obstruction include strutive, oxalate, and urate. These minerals can mix to form urethral plugs and urinary stones of varying size and consistency. Some materials are softer and easier to break apart or pass, while others will be too solid to pass and require surgery to remove. Srutive stones can generally be dissolved before they cause a serious obstruction- while oxalate and urate stones tend to require more advanced procedures.

Two procedures used to remove urinary stones in cats are a cystotomy, a surgery that entails opening the bladder to allow for the direct removal of the obstruction, and urohydropropulsion, in which a catheter is used to flush out the bladder with a saline solution. In any event, it’s likely that obstructions will recur in cats that have developed them; therefore, it’s important to take precautionary measures to prevent the formation of a second obstruction after either procedure.

Struvic & Urate Stones

To prevent future stones from forming, it’s crucial to make changes to your cat’s dietary habits. Because each type of stone has a different mineral composition, the prevention methods for each type of stone is different. For instance, struvite stones can typically be dissolved in cases where they are not currently obstructing the urethra. Special formulas can also make the urine more acidic in the hopes of dissolving struvic stones.

Once the stone is obstructing the kidney, however, it must be removed. To prevent each stone from forming, controlling the pH of your pet’s urine can become a routine task. In her UC Davis Veterinary Medicine protocol for treating urate urolithiasis in dogs and cats, Westropp (n.d.) recommends ensuring that your pet’s urine remains acidic, meaning that its pH level stays at 6 or below. By restricting protein, phosphorous, and magnesium, a specialized diet can compensate for the kidney- which would normally filter these out of your pet’s blood.

Urate stones are rare in cats and the subtleties of their formation are still largely a mystery. There are, however, established methods of dissolving and preventing these stones. Unlike struvic stones, the best way to dissolve urate stones is to increase the pH of your cat’s urine to make it more basic, resulting in a pH greater than 7. This process reduces the amount of ammonia produced by the renal system.

Westropp (n.d.) also recommends feeding your cat a moist diet that is low in protein to reduce the amount of urate in the urine relative to other compounds. This diet can also be imperative in the effort to prevent future urate stones from forming.

Calcium Oxalate & Cystine Stones

Unlike struvic and urate stones, calcium oxalate and cystine stones cannot easily be dissolved. Calcium oxide and cystine stones, for example, cannot be dissolved at all- only prevented. And although keeping your cat’s urine acidic may be effective for preventing strutive stones, slightly more basic urine is desired for preventing oxalate uroliths. Diets with potassium citrate help keep the pH balance at the desired level, in a range between 6.5 and 7.5. It can also help to ensure your cat consumes an adequate amount of water.

Cystine uroliths are rare in cats- but there are protocols for their dissolution and prevention. To dissolve these stones, there is no method that is guaranteed to work- but it is suggested that you attempt to increase the pH of your cat’s urine until it is more than 7 such that the urine is basic. This can also help prevent future cystine stones from forming.

Though Pierson (2013) cautions against performing the procedure prematuerly, a perineal urethrostomy can prevent future obstructions from forming. This surgery entails removing the narrow part of the urethra as well as a large portion of the penis for male cats. The result is a wider opening that allows for a less obstructed tract. It’s important to note, however, that this procedure should be used only as a last resort, as it can cause urinary incontinence and other bladder diseases. Additionally, patients can expect bleeding for up to ten days after the surgery.

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Urinary tract cancer is rare in cats, affecting only 1-5% of cats diagnosed with FLUTD; however, it can be life-threatening to those diagnosed. Rhabdomyosarcoma are malignant tumors that form in the kidneys, bladder, or urethra of your cat. If left untreated, these tumors will eventually metastasize throughout the renal system, before quickly spreading to other internal organs, as well as to your cat’s lymph nodes (“Renal Tumors – Feline”, n.d.).

Symptoms

In addition to the typical symptoms of FLUTD, cats suffering from cancer might exhibit an inability to urinate. X-rays, ultrasound, and urinalysis may help to detect tumors in pets exhibiting these symptoms. For a definitive diagnosis, a histopathology- or microscopic examination of stained tissue- should be performed. A histopathology report will give a comprehensive prognosis when combined with the type, location, and differentiation (or appearance) of a tumor.

Causes

Cancer has many causes and it can be difficult to determine an exact catalyst to its inception and proliferation; some external factors that are known to contribute to cancer include radiation, chemicals, hormones and infections. Each of these possible factors has the potential to alter the genetic regulation of cells; these genetic alterations prevent the genes from regulating cell death, causing the unnatural growth of tissue. Congenital abnormalities in which an organ’s cellular structure develops in an atypical manner before birth can also cause cancer to develop.

Cancer is more likely to occur when cells are rapidly expanding, as is the case in the formation of organs. One type of cancer, nephroblastoma, develops as a result of abnormal kidney tissue growth while in the womb. Renal nephroblastoma in cats is uncommon but highly malignant, often spreading to the lungs and liver. This type of cancer is generally diagnosed within the first year of a cat’s life and is graded as favorable or unfavorable as determined by a histology report.

The College of Veterinary Medicine at Cornell University