Escherichia coli-associated follicular cystitis in dogs: Clinical and pathologic characterization.

Background: Follicular cystitis is an uncommon inflammatory change in the urinary bladder wall characterized by the formation of tertiary lymphoid structures (TLSs) in the submucosa.

Objectives: To characterize clinical and pathologic features of follicular cystitis in dogs and to explore in situ distribution and possible role of Escherichia coli as an associated cause.

Animals: Eight dogs diagnosed with follicular cystitis and 2 control dogs.