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Feline Lower Urinary Tract Disease

Feline lower urinary tract disease (FLUTD) is a generalized condition that affects the bladder or urethra of cats. Cats with FLUTD exhibit similar, recognizable clinical signs, including:

  • Difficult or painful urination
  • Increased frequency of urination or increased attempts to urinate
  • Excessive grooming of the genital area
  • Inappropriate urination, urinating outside of the litter box, prolonged time in the litter box
  • Blood in the urine

FLUTD can be caused by a variety of conditions; including infection (bacterial, fungal, parasitic), stones or crystals within the bladder or urinary tract, urethral plugs, cancer, or inflammation (cystitis), which may be of an undetermined cause. The condition may occur in cats of any age but is more common in young to middle-aged cats. Males and females are equally affected. Neutered males or spayed females may be at increased risk of FLUTD. Indoor cats, cats in multi-cat households, overweight cats, and those cats on dry food-only diets are more predisposed to FLUTD. Stressful events (changes in routine, moving, boarding) have also been identified as possible causes of FLUTD.

Because FLUTD can be caused by many different problems, diagnosis can be difficult. After physical examination, a urinalysis will be performed. Other tests, including blood work, abdominal radiographs (x-rays), urine culture and sensitivity, and abdominal ultrasound may be recommended. Other physical problems, like neurologic disease (causing incontinence) or arthritis of the lumbar spine or hips may make it difficult for a cat to urinate normally. Therefore, it is important to pursue all recommended diagnostics in order to try to identify the cause of the urinary difficulty.

Treatment is based upon the results of diagnostic testing and is different depending on the cause of FLUTD. In many cases, clinical signs will spontaneously resolve within a week, regardless of treatment. However, recurrence of FLUTD is common, with an estimated 40–50% of cats exhibiting recurrence within 1 year of initial diagnosis.

Causes of FLUTD

Feline Idiopathic Cystitis (FIC)

FIC is the most common diagnosis made in cats with FLUTD. FIC is a diagnosis of exclusion, meaning other causes of FLUTD must first be ruled out. Cystitis is inflammation of the bladder wall which produces pain and causes difficult and/or frequent urination, often with blood in the urine. The exact cause of cystitis is unknown and has been the subject of multiple studies within the last 30 years. Women are also subject to a form of cystitis that is also not well understood. Symptoms associated with FIC often resolve spontaneously within a few days to weeks regardless of treatment. However, recurrence is common, so treatment is focused on reducing the duration of episodes and preventing subsequent recurrences. FIC can be frustrating to treat given the intermittent signs and possibility of frequent recurrence. Often, pain medication will be prescribed to alleviate discomfort. Fluids may be given in order to flush the bladder. In severe cases, anti-inflammatory medications may be prescribed. Dietary changes are very commonly recommended, including transitioning to a mostly canned diet. Studies have shown that cats on canned diets have a 19% risk of developing FLUTD while those on dry diets have a 59% chance.

Stress appears to be an important factor in the development of FIC: multiple cat households or the addition of a new pet, changes in the environment, food schedule changes, indoor-only cats, dry only diets and boarding or moving have all been linked to FIC. Changes in an owner’s schedule (vacations, work travel, new jobs) have been linked to FIC occurrence. Therefore, stress reduction, through environmental enrichment, is important in preventing FIC. In refractory cases, anti-anxiety medications or behavioral medications may be prescribed to help reduce stress.

Urinary Stones (Uroliths)

Uroliths may form in any part of the urinary tract and can occur in up to 25% of FLUTD cases. Uroliths occur when excess minerals that are part of the diet precipitate in the urinary tract and form crystals. These crystals may then coalesce and form deposits, or stones. While crystals may be visible in a urinalysis, a radiograph or an ultrasound is needed to diagnose uroliths.

Treatment of uroliths depends upon the mineral composition of the stones. Often, surgical removal of the stones is required to determine the mineral composition. Surgery is also helpful to reduce clinical signs of discomfort. Although there are many different possible types of uroliths, there are two that are considered most common: struvite (magnesium ammonium phosphate) and calcium oxalate. Regardless of composition, canned foods are recommended over dry foods because the extra moisture will help dilute urine and make crystal or stone formation of any kind less likely. Also, prescription diets that are formulated to treat and prevent crystals or stones may be recommended.

With struvite crystals or stones, an acidifying diet that is low in magnesium and phosphorous may be prescribed to try to dissolve the stones or to prevent crystal and stone formation. Most commercial diets are now formulated to reduce the likelihood of struvite formation. In some cases, when diet modification is not successful, surgical removal may still be necessary.

Calcium oxalate stones cannot be dissolved by diet modification-these types of stones must be removed surgically. Diets lower in calcium with a modified pH have been formulated to help prevent formation.

Urethral Obstruction

Urethral obstruction occurs when the urethra becomes partially or totally blocked, preventing normal urination. Complete urethral obstruction is a MEDICAL EMERGENCY as the inability to urinate causes acute kidney failure and electrolyte imbalances that can be fatal.

Male cats are at a greater risk of obstruction due to their longer, narrower urethral passage. The most common causes of obstruction are uroliths and urethral plugs-which are composed of minerals, mucous, and cellular material. Plugs can also occur as a result of bladder infection. While signs are similar to cases of FLUTD, cats with urinary obstruction will not pass urine or can only pass small amounts (often only a few drops at a time). The cat will become increasingly depressed and other signs like decreased appetite, dehydration, vomiting, and eventually death may occur the longer the obstruction is present.

Treatment requires the passage of a urinary catheter to relieve the obstruction. This typically requires sedation or anesthesia. Fluid therapy is instituted to treat dehydration and electrolyte imbalances. Hospitalization and treatment may be needed for several days to weeks depending on the severity and duration of the obstruction. The possibility for re-obstruction due to inflammation and scarring of the urethra is high. If this occurs, a surgery called a perineal urethrostomy may be recommended. The surgery removes the narrow portion of the urethra, thus widening the urinary passage. Once the cause of the obstruction has been determined, treatment can be more accurately directed at the cause; special diets or medications to dissolve crystals, surgery for removal of stones, or antibiotics in case of infection. Again, canned food is always preferred over dry in cats with FLUTD in order to dilute urine and promote more frequent urination.

Urinary Tract Infections

In about 2% of FLUTD cases, clinical signs are due to bacterial or rarely, fungal urinary tract infections. Once the infection is detected by urinalysis, culture, and susceptibility may be performed to identify the type of organism involved and what antibiotics or medications it is susceptible to. Antibiotics may then be prescribed. Length of treatment will depend on the frequency of infections and the presence of other diseases like kidney disease or diabetes mellitus. Abdominal radiographs may also need to be taken to rule-out uroliths.

Prevention involves a combination of dietary and environmental management in order to reduce the severity and duration of episodes.

  1. Increase fluid intake
    • Canned diets-Studies have shown that recurrence of FLUTD in cats can be reduced significantly by transitioning them to a canned diet. A study by The Ohio State University showed a recurrence rate of 39% in cats on dry diets, while only 11% of cats on canned foods had a recurrence of symptoms.
    • Provide fresh, clean water at all times
    • Offer flavored water as a treat: add tuna or clam juice or low-sodium chicken broth to water, but make sure to provide access to non-flavored water as well!
    • Try various drinking receptacles to see if your cat has a preference
      • Ceramic vs. metal or glass dishes or cups
      • Recirculating water fountains
      • Elevating water dishes to neck level for older cats
  2. Cats that have been diagnosed with uroliths should be fed diets that are balanced pH and lower in magnesium, phosphorous, and calcium.
    • Urine acidifiers may be prescribed in some cases with struvite crystals or stones if dietary management alone is not successful
  3. Provide an adequate number of litter boxes in multiple locations
    • The general recommended number is one litter box per cat plus one extra.
  4. Keep litter boxes in a quiet area, inaccessible to young children and dogs
  5. Scoop litter boxes daily, clean litter boxes with warm water monthly
  6. Minimize changes in routine
  7. Provide environmental enrichment
    • Use cat trees or climbing toys
    • Encourage predatory behavior by hiding treats and toys or using treat balls

A recheck urinalysis is recommended 1–2 weeks after therapy has been initiated in order to monitor response. We understand that FLUTD can be a very frustrating issue to treat. We are here to help you manage this disease and help keep your cat as comfortable as possible.

Adapted from Feline Lower Urinary Tract Disease Cornell Feline Health Center 2006. 

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