Follicular cystitis in a dog

A four‐year‐old female Cavalier King Charles Spaniel with a history of recurrent lower urinary tract disease refractory to treatment was referred to our hospital. Clinical examination was unremarkable apart from thickening of the dorsal vulva. Abdominal ultrasound was compatible with possible areas of mild thickening of the bladder wall. Lower genitourinary‐contrast radiographic studies showed multiple small lesions in the bladder wall. Surgical biopsy of the bladder was compatible with follicular cystitis and excised uterine tissue was consistent with cervicitis. Clinical signs resolved after treatment with a combination of antibiosis, NSAIDs, pentosan polysulfate and amitriptyline. Follow‐up 30 months after surgery confirmed that the dog was free of clinical signs. Follicular cystitis has not been previously reported in dogs but should be considered as a differential for patients with refractory long‐standing lower urinary tract disease.