Feline lower urinary tract disease (FLUTD) is an umbrella term for diseases of the bladder and urethra in cats. Cats with FLUTD may show a variety of urinary signs, including frequent urination, urinating outside the litter box, painful urination, straining to urinate, blood in the urine, or the inability to urinate.
FLUTD can occur secondary to several disease processes including feline idiopathic cystitis (FIC), urinary stones, urine crystals, and urinary tract infections. Importantly, in male cats, lower urinary signs due to any of these disease processes may progress to a life-threatening urethral obstruction (inability to urinate). Urethral obstruction requires emergent treatment for stabilization, urinary catheterization, and hospitalization for supportive care. In cases of recurrent urethral obstruction, surgery (perineal urethrostomy) may be advised.
Feline idiopathic cystitis is a common cause of FLUTD. A diagnosis of FIC requires that other diseases are first excluded. FIC refers to inflammation of the bladder and urethra in the absence of an infection, crystals, stones, or other structural bladder or urethral disease. There are several factors that may increase the risk of FIC including emotional or environmental stress which might occur in a multi-cat household or with a change in your cat’s routine.
Cats can develop bladder stones (cystoliths) which may cause urinary tract signs or urethral obstruction. Bladder stones should be ruled-out in male cats with a urethral obstruction and in female cats with chronic urinary tract signs. Certain stones can be seen on radiographs (x-ray), while others cannot. The latter stone types may be seen with ultrasound or other specific imaging techniques. For cases in which urethral obstruction occurs secondary to stones, surgery is often advised as soon as it’s safe to do so. Stones can be submitted for analysis to determine if diet modifications may be helpful to minimize the risk of recurrence.
Compared to dogs, cats develop urinary tract infections relatively infrequently. Older cats and cats with underlying diseases including bladder stones, diabetes mellitus, or kidney disease are at increased risk for UTIs. Cats with UTIs should be evaluated for these other disease processes as well. UTIs are diagnosed with a combination of urine testing including urinalysis and urine culture. Because a urinalysis may show inflammation with or without infection (see FIC above), urine culture is very helpful for identifying a bacterial infection and guiding antibiotic therapy. When possible, a urine culture should be repeated 5-7 days after antibiotic therapy is complete to ensure resolution of the infection.