Congenital or hereditary urethral anomalies are uncommon in all domestic species. They include urethral agenesis, imperforate urethra, hypospadias, epispadias in combination with bladder exstrophy, urethral duplication, urethral diverticula, urethrorectal fistula, and urethral stenosis.
Hypospadias in Animals
Hypospadias is a developmental defect resulting from failure of the urethral grooves to fuse during phallus elongation. As a result, the urethral opening (meatus) is ventral and caudal to the tip of the penis and is classified based on anatomical localization as glandular, penile, scrotal, perineal, or anal. The penis or scrotum may be underdeveloped, as well.
This uncommon anomaly is most frequently observed in male dogs; the highest prevalence is among Boston Terriers, suggesting a genetic basis. The condition is also rarely observed in bulls.
Clinical signs depend on the site of the urethral meatus and include urine scalding and increased susceptibility to urinary tract infection.
Although surgical correction also depends on the site of the urethral meatus, a modification of the prescrotal urethrostomy is generally useful.
Urethrorectal and Rectovaginal Fistulas in Animals
Urethrorectal and rectovaginal fistulas are congenital anomalies that predominantly affect dogs, cats, and horses.
Urethrorectal fistulas are more common in males than females. In dogs, English Bulldogs seem to have a breed predisposition, possibly as a congenital defect due to abnormal separation of the embryonal cloaca into the urethra and rectum.
In females, rectovaginal fistulas are more common than urethrorectal fistulas.
Clinical signs include hematuria and dysuria secondary to urinary tract infection. Simultaneous passage of urine from the anus and urethra during micturition may be noted.
Appropriate treatment consists of surgical correction and concurrent management of urinary tract infection.
KeyPoints
Congenital or hereditary urological anomalies are uncommon among domestic animals.
Clinical signs, such as renal dysfunction or abnormalities in micturition, relate to the specific anomaly.
Treatment generally involves surgical correction of anatomical abnormalities and medical management to control associated clinical signs.
For More Information
Familial and congenital renal diseases of cats and dogs. In: Ettinger SJ, Feldman EC, Cote E, eds. Ettinger’s Textbook of Veterinary Internal Medicine. 9th ed. 2023; Elsevier.
Congenital lower urinary tract disorders. In: Ettinger SJ, Feldman EC, Cote E, eds. Ettinger’s Textbook of Veterinary Internal Medicine. 9th ed. 2023; Elsevier.
Kruger JM, Osborne CA, Lulich JP, Oakley RE. Inherited and congenital diseases of the feline lower urinary tract. Vet Clin North Am Small Anim Pract. 1996;26(2):265-279.
