Case description: A 4-month-old 5.9-kg sexually intact female French Bulldog was presented because of recurrent urinary tract infections in combination with pollakiuria, hematuria, and urinary incontinence.
Clinical findings: A diagnosis of malakoplakia was made on the basis of results of hematologic and serum biochemical testing, abdominal ultrasonography, bacterial culture, and cystoscopic biopsies of the urinary bladder wall. Biopsy samples were sent for routine histologic examination and fluorescence in situ hybridization to confirm the presence of intracellular and subendothelial bacteria.
Treatment and outcome: Treatment with enrofloxacin was started after the diagnosis of malakoplakia was confirmed. During treatment, polypoid changes in the urinary bladder decreased dramatically but did not disappear. On follow-up ultrasonography after 12 weeks of treatment, marked improvement was visible and results of repeated bacterial culture and fluorescence in situ hybridization of bladder wall samples were negative. The patient was free from clinical signs and had an ultrasonographically normal urinary bladder 59 weeks after antimicrobial treatment was discontinued.
Clinical relevance: Malakoplakia, a granulomatous disease characterized by impaired histiocytes that are unable to completely digest phagocytized bacteria, is a very rare disease in dogs, but early suspicion of the condition is essential to allow timely diagnosis and avoid disease progression and the need for prolonged treatment. Malakoplakia should be considered in young dogs with chronic urinary tract infections; the diagnosis can be made through a combination of histologic examination and fluorescence in situ hybridization of bladder wall biopsy samples.