Kruger JM, Lulich JP, et al. Comparison of foods with differing nutritional profiles for long-term management of acute nonobstructive idiopathic cystitis in cats. J Am Vet Med Assoc. 2015 Sep 1; 247(5):508-517.
When cats are diagnosed with feline idiopathic cystitis (FIC), they are considered to have a naturally occurring lower urinary tract (LUT) disease of unknown etiology. FIC is the most common cause of hematuria (presence of blood in the urine), dysuria (vocalizing due to painful urination), poillakuria (increased frequency of urination), and periuria (urinating around the house or outside the litter box) in male and female cats. A fifth sign, stranguria (persistent but nonproductive straining or posturing to urinate) also occurs and urinary obstruction may occur in some male cats. Over 70 agents or procedures have been recommended for prevention or treatment of FIC but few controlled, clinical trials have been done. Determining efficacy of treatments is difficult due to the self-limiting nature of clinical signs related to most episodes of FIC. The clinical signs previously detailed often subside within 2 to 7 days in the majority of cats with acute nonobstructive idiopathic cystitis.
In this study, the authors performed a randomized, controlled, masked clinical trial to evaluate the effect of nutrition on recurrent signs of LUT disease in cats with FIC.
Thirty-one cats with acute nonobstructive idiopathic cystitis that were eligible were enrolled in the study. The cats entering the study were randomly assigned to be fed either a cystitis-prevention food or a control food. The multipurpose prevention food was a commercially available feline food designed for struvite prevention and dissolution and calcium oxalate prevention with increased antioxidants and fatty acids added. The control food was custom manufactured to be balanced and to deliver a targeted neutral urine pH.
Cats enrolled were fed one of the two foods. In addition, owners documented for the 5 LUT signs daily for up to one year. The number one endpoint was the number of recurrent episodes in which a cat had multiple (2 or more concurrent) LUT signs within a day (considered a multiple-sign day) for the duration of treatment. Multiple sign days occurring on consecutive days were considered a single incident; episodes were considered independent if there was a 2-day gap between events. Short-term opioid treatment for analgesia using either buprenorphine or butorphanol was permitted in patients with recurrences associated with signs of pain. Selection of wet or dry formulation of food was by owner’s preferred choice.
The documented findings showed that the proportion of cats fed prevention food having 1 or more recurrent episodes of multiple-sign days (4/11) was not significantly lower than that of cats fed control food (9/14). However, feeding the prevention diet significantly reduced the mean incidence rate of recurrent episodes of multiple-sign days by almost 8-fold compared to cats fed control food. The understanding of incidence rate is it measures the frequency with which new episodes of clinical signs occurred over time in the study population. Episodes of single LUT signs were also significantly reduced.
Further observations were also noted. The specific components responsible for the beneficial effect of the food were not determined. The authors hypothesized that the beneficial effects most likely were due to the anti-inflammatory effects associated with the increased concentrations of anti-oxidants and omega-3 fatty acids in the prevention food. If crystalluria was present in cats fed the prevention food or control diet was primarily struvite, calcium oxalate crystalluria was not observed in cats of either food group. They underscored male cats undergoing an acute episode of FIC are at risk of urethral obstruction. The prevention diet, in conclusion, was of benefit in reducing episodes of multiple sign days and episodes of hematuria, dysuria, and stranguria in cases of acute FIC. From this study, no determination can be made of the role of wet versus dry food on the recurrence of FIC or the effect of nutrition on the chronic form of the disease. (VT)