Efficacy of intravesical pentosan polysulfate sodium in cats with obstructive feline idiopathic cystitis

Objectives Obstructive feline idiopathic cystitis is a common emergency in small animal practice. There is evidence for a defective glycosaminoglycan layer in the urinary bladder of affected cats. The aim of this study was to investigate the effect of intravesical pentosan polysulfate sodium (PPS) in cats with obstructive feline idiopathic cystitis in a randomised, placebo-controlled, blinded clinical study. Methods Thirty-five cats with obstructive feline idiopathic cystitis were enrolled into the study. On day 0, cats were randomised to receive either 30mg PPS in saline (18 cats) or saline alone as placebo (17 cats) at the time of indwelling urinary catheter placement and then after 24 and 48h. The catheter was clamped for 30mins after administration before connecting it to a sterile urine collection system. The procedure was repeated after 24 and 48h, and then the indwelling catheter was removed. Treatment success was assessed via the incidence of recurrent urethral obstruction, results of a scoring system for physical examination and daily urinalysis from day 0 to 5. Results Recurrent urethral obstruction occurred in 3/18 cats of the verum group and 3/17 of the placebo group (P=1.000). The verum group showed a significantly lower degree of microscopic haematuria between day 5 and day 0 (P 0.05). The placebo group showed a significantly lower degree of dipstick haematuria between day 5 and day 0 (P 0.05). There was no difference in the clinical score between the groups in the investigated time period. Conclusions and relevance Intravesical instillation of PPS three times within 48h in the chosen dose had no influence on the incidence of recurrent urethral obstruction and clinical signs in cats with obstructive feline idiopathic cystitis