Abstract
BACKGROUND: Polypoid cystitis (PoC) in dogs is associated with chronic inflammatory bladder conditions and is discovered during evaluation for signs of lower urinary tract disease, or incidentally. OBJECTIVE: To describe PoC in dogs evaluated in an academic practice. ANIMALS: Dogs with confirmed (n = 59) or presumptive (n = 53) PoC were evaluated between January 2004 and October 2020. METHODS: For this retrospective study, medical records were searched for PoC. RESULTS: The most common presenting signs of 112 dogs with PoC were hematuria (n = 42; 38%), stranguria (n = 28; 25%), and pollakiuria (n = 25; 22%). Polyps were found incidentally (n = 13; 12%). Urinary tract infection (UTI; n = 61; 54%) or urolithiasis (n = 38; 34%) was a common presumptive cause. Escherichia coli (n = 39; 53%), Enterococcus faecalis (n = 14; 19%) and Staphylococcus pseudintermedius (n = 5; 7%) were isolated from dogs with UTI. Ultrasonographic findings (n = 101) included polypoid structures (n = 44; 44%), broad-based masses (n = 16; 26%), and bladder wall thickening (n = 25; 25%); mostly in the cranioventral bladder apex (n = 56; 80%). Of 41 specimens tested, none had evidence of the BRAF V595E mutation. Urinary tract neoplasia was not reported in any dog during follow-up (range 1 month-8.4 years; median 8 months). Interventions included antibiotic or anti-inflammatory administration, and surgical or cystoscopic ablation. During follow-up, recurrent signs of lower urinary tract disease were reported in 23 (20%) dogs. CONCLUSIONS AND CLINICAL IMPORTANCE: History of either UTI or urolithiasis, compatible imaging findings, and absence of detectable BRAF V595E mutation support the presumptive diagnosis of PoC in dogs. Affected dogs have a good prognosis, warranting differentiation from other urinary tract diseases.