Retrospective interview-based long-term follow-up study of cats diagnosed with idiopathic cystitis in 2003-2009.

The aim of this study was to register long-term recurrence rates and mortality rates in cats diagnosed with feline idiopathic cystitis (FIC), with an observation period until death or a minimum of 10 years. Data regarding recurrence of signs of feline lower urinary tract disease (FLUTD) and FLUTD-related mortality in cats diagnosed with FIC between 2003 and 2009 were obtained through structured telephone interviews with the cat owners from December 2018 until February 2019. The interviews were based on a standardised questionnaire covering whether the cat was still alive or not, whether death/euthanasia were due to FLUTD and whether the cat had experienced recurrent episodes of clinical signs of FLUTD. If recurrences had occurred, exact numbers or estimates of 1-3, 4-6 or >6 recurrences were recorded. The owners of 50/105 FIC cats included in a previous study (48%) were available for inclusion in the present study. At the time of the interview, only 6/50 cats (12%) were still alive. The FLUTD-related mortality rate was 20% (n = 10/50). Twenty-three cats (46%) had no recurrences, three cats (6%) were euthanased shortly after diagnosis, nine cats (18%) had 1-3 recurrences, three cats (6%) had 4-6 recurrences and six cats (12%) had >6 recurrences. For the remaining six cats, the number of recurrences was uncertain. The long-term prognosis for cats diagnosed with FIC may, based on the results from the present study, be regarded as fairly good, as approximately 70% of the cats either recovered without additional episodes, experienced only a few recurrences, are still alive after a minimum of 10 years since inclusion in the study, or were euthanased for reasons unrelated to FLUTD.