What is Feline Lower Urinary Tract Disease?
Feline Lower Urinary Tract Disease (FLUTD) isn’t a single entity, but a group of conditions with shared symptoms. FLUTD is an extremely common health problem of cats, and yet is among the most challenging to diagnose and treat. Anyone who has lived with a cat with FLUTD knows the anguish and frustration it can cause. Symptoms of FLUTD are the result of a painful, inflamed bladder (also known as cystitis) and may include any or all of the following:
- Pain or difficulty while urinating
- Increased frequency of urination
- Vocalizing while urinating
- Blood in the urine
- Excessive licking at the genital area
- Urinary “accidents” outside the litter box
FLUTD is most common in young to middle-aged cats, and it affects males and females with equal prevalence. However, males are much more likely than females to develop a life threatening urinary obstruction (see below). Lower urinary tract trouble occurs more often in indoor cats that live in multi-cat families, eat dry food, and are overweight and relatively sedentary. Environmental factors such as social strife among multiple cats and changes in the household routine can also play a part.
What are the causes of FLUTD?
Just about anything that causes irritation or inflammation in the bladder can cause lower urinary tract disease. The top five factors, in order of prevalence, include:
- Feline Idiopathic Cystitis. Idiopathic means “arising from an unknown cause” and in fact the cause of Feline Idiopathic Cystitis (FIC) has yet to be elucidated. Nonetheless, it is the most common lower urinary tract disease in cats. In FIC, the bladder wall becomes swollen and inflamed. Cats with idiopathic cystitis make frequent attempts to urinate, strain and vocalize while doing so, and their urine may contain blood. FIC tends to have a relapsing and remitting course, with episodes lasting 1–2 weeks, resolving spontaneously, then recurring without warning. Veterinarians have identified several factors that may trigger FIC, which include:
- Stress. Research has shown many parallels between FIC and a bladder disorder that occurs in women called Interstitial Cystitis. Investigators note that interstitial cystitis is often triggered by a psychologically stressful event, and the same seems true in cats. Biopsy samples show similar changes. It’s thought that in both cases stress hormones may chemically activate inflammatory cells and pain receptors in the bladder wall. Stress triggers in cats could include social discord among animals in the house, a change in diet or feeding schedule, or the absence of a preferred person. FIC is a rule out in any case of feline inappropriate urination.
- Diet. Cats fed a primarily dry diet tend to produce highly concentrated urine. Highly concentrated solutes may actually irritate the bladder wall.
- Increased bladder wall permeability. Infectious agents or a chemical imbalance may actually erode the watertight lining that shields the bladder wall, allowing bladder contents to damage the sensitive tissue underneath.
- Bladder Stones. Bladder stones are rock-hard concretions of minerals such as calcium, magnesium or phosphate. They form in the bladder over time due to chemical and pH imbalances and are aggravated by overly concentrated urine. Their rough surface abrades the bladder wall and serves as a perfect place for bacteria to grow. Your veterinarian may suspect bladder stones by finding microscopic crystals or pH imbalances in the urinalysis. Most bladder stones can be diagnosed on x-rays or ultrasound. Treatment often requires surgical removal, although some stones can be chemically dissolved using a special diet. Cats who have had bladder stones are susceptible to recurrences. Special medication and diet are often recommended to prevent this.
- Urethral Obstruction. This is the most notorious problem associated with FLUTD, and the most serious. It occurs when a cat’s urethra, the narrow tube through which urine exits the bladder, becomes partially or completely blocked. The most common culprits are urethral plugs. These are soft, sticky aggregations of dead cells, mucus, and mineral crystals that travel partway down the urinary tube and then get stuck. Current research suggests that FIC is responsible for the inflammation that causes these plugs.
- Bladder infection. A bacterial infection of the bladder is common in women and in dogs, but unusual in the cat. When it occurs, it is often related to other conditions such as diabetes, kidney disease, bladder stones, or an anatomical defect of the bladder. When bladder infection occurs, it is usually in an older cat. Diagnosis is made based on urinalysis and urine culture. Blood tests, x-rays and ultrasound are usually necessary to rule out the associated diseases.
- Bladder cancer. Bladder cancer occurs in cats, but it is rarely seen in cats under the age of 10 years. Diagnosis is via urinalysis, x-rays, ultrasound and biopsy. Some tumors can be surgically removed depending on their location; others are treated with antibiotics and anti-inflammatories.
In theory, FIC is a diagnosis by exclusion, meaning that all other diseases must be ruled out first. Practically speaking, many veterinarians can make the diagnosis based a cat’s age, symptoms and urinalysis findings, without resorting to the full battery of tests.
Urethral obstruction occurs almost exclusively in male cats, in whom the urethra is especially long and narrow. It is a life-threatening medical emergency. Back pressure from the obstructed urethra first distends the bladder to a painful size, then shuts down the kidneys, which are then unable to remove toxins and maintain electrolyte balance in the body. If the obstruction is not relieved, death will occur within 24–48 hours. If your male cat is showing lower urinary tract signs and you’re unsure if he is able to pass urine, seek veterinary care immediately.
The symptoms of urethral obstruction begin like any case of FLUTD, with frequent and painful urination. However, as time progresses, the cat becomes increasingly distressed and may vomit, howl or cry out in pain. Your veterinarian can diagnose urethral obstruction immediately on physical examination by feeling the firm, distended bladder. Emergency treatment usually involves the use of a fine-gauge catheter to displace the urethral plug and restore urine flow, followed by aggressive fluid treatment and supportive care over several days.
How is FLUTD treated?
The treatment of FLUTD depends on the cause, if it can be identified. A true bacterial cystitis is treated with antibiotics; bladder stones are removed surgically or dissolved using a special diet; urinary obstruction is treated as described above.
Treatment of FIC is controversial and is based more on anecdotal reports on than hard science. Since most flare-ups resolve on their own in a week or two, nearly any remedy may appear to work at first. There is no treatment to date that reliably prevents FIC in the long run, however. Antibiotics and anti-inflammatories, such as prednisone, are often tried. Certain anti-anxiety medications have shown promise in some clinical trials but proven disappointing in others. Your veterinarian can best advise you on how to manage your cat’s lower urinary tract troubles.
Some cats may have a few bouts of FLUTD and be done with it; others are unfortunate enough to suffer frequent recurrences. Regardless of cause, there are several measures that can decrease the frequency or severity of attacks.
- Feed a high-quality diet. Your veterinarian may recommend a specific prescription diet or suggest appropriate over-the-counter foods to try. Many of these diets are designed to provide a healthy pH balance in the urine while minimizing problematic waste products.
- Feed canned food. The moisture in the canned food helps create a more dilute urine.
- Promote water intake. Provide multiple water bowls, refresh them frequently, or consider purchasing a re-circulating water fountain designed especially for cats.
- Provide an adequate number of litter boxes and keep them impeccably clean.
- Address the sources of social stress among the cats in your home. Your veterinarian or a licensed veterinary behaviorist can help you sort this out.
- Minimize major changes in the family routine.