Merck Manual

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Professional Version

Bladder Anomalies


Scott D. Fitzgerald

, DVM, PhD, DACVP, DACPV, Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University

Reviewed/Revised Jul 2013 | Modified Nov 2022
Topic Resources

Urachal Remnants:

Congenital anomalies resulting from incomplete urachal closure include patent urachus, urachal diverticulum, umbilical urachal sinus, and intra-abdominal urachal cyst. These conditions may be seen in any domestic species but are most frequently a clinical problem in cats, dogs, and horses. Clinical signs and appropriate therapy depend on the type of anomaly. Patent urachus is typically associated with continuous urinary incontinence, urine scalding of the ventral abdomen, and development of bacterial urinary tract infections. Urachal diverticula also predispose to urinary tract infection by serving as a nidus for bacteria. Definitive diagnosis of both disorders is by positive contrast cystography. Treatment consists of surgical resection and 2–4 wk of appropriate antibiotic therapy when indicated. Surgical resection is the standard treatment for umbilical urachal sinuses and intra-abdominal urachal cysts.

Miscellaneous Bladder Anomalies:

Bladder duplication, dysplasia, hypoplasia, agenesis, and exstrophy (congenital eversion) have been reported and are often associated with other urinary tract defects. Diagnosis is by physical examination, observation of micturition, and contrast radiography. Clinical signs and therapy depend on the type of anomaly.

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