How would you manage a prolapsed urethra in an English Bulldog?
A 3-year-old male non-castrated English Bulldog was admitted to the Veterinary Medical Center because of intermittent episodes of gross hematuria of two months' duration.
What is the cause of urethral prolapse?
Prolapse of the mucosal lining of the distal portion of the urethra through the external urethral orifice occurs primarily in young male dogs. Although this disorder has been encountered in several different breeds, it occurs primarily in young (mean age ~18 months; range 4 months to 5 years of age) English Bulldogs and Boston Terriers.
We have hypothesized that the predilection of brachycephalic English Bulldogs and Boston Terriers to urethral prolapse may be related to abnormal development of the urethra with superimposed increased intra-abdominal pressure as a consequence of labored breathing, dysuria or sexual activity. Increased intra-abdominal pressure could impair venous return of blood through the pudendal veins, predisposing susceptible dogs to engorgement of the corpus spongiosum surrounding the distal urethra. The observation that English Bulldogs are predisposed to congenital urethrorectal fistulas supports the hypothesis that maldevelopment of the urethra may be involved. Increased intra-abdominal pressure secondary to stertorous breathing caused by stenotic nares and abnormal elongation of the soft palate may impair venous return from the penis. Detection of urocystoliths and vesicourachal diverticula in some affected dogs suggests that increased intra-abdominal pressure secondary to dysuria may also be a predisposing factor. The observation that urethral prolapse is more severe when male dogs are sexually active may be linked to distension of submucosal vascular channels located in the penis.
What other diagnostic procedures would you recommend?
The dog could urinate normally. However, results of analysis of a voided urine sample revealed numerous red cells, a few white cells, moderate proteinuria and a specific gravity of 1.035. Evaluation of a urine sample collected by cystocentesis following collection of the voided urine sample revealed two to three red cells per high power magnification (450X), a trace of protein, and a urine specific gravity of 1.032. Aerobic culture of both urine samples for bacteria revealed no growth. Evaluation of prostatic fluid collected during manually induced ejaculation revealed no abnormalities.
Evaluation of a CBC was normal. Evaluation of a contrast urethrocystogram, and double-contrast cytogram revealed no anatomic abnormalities.
Although not applicable to this case, if the prolapsed portion of the urethra is to be surgically removed, it should be placed in formalin (or other suitable tissue fixative) for examination by light microscopy. Lack of deep-seated inflammation and scarring may suggest that recurrence is less likely.
In contrast, mucosal ulceration, extensive inflammation, necrosis and scarring may indicate that problems are more likely to recur.
What is the biologic behavior of a prolapsed urethra?
The biologic behavior of untreated urethral prolapses has not been evaluated in a large number of cases. This may be related to the fact that most textbooks recommend some form of surgery to treat prolapsed urethras. Cases reported in the literature have typically been managed by manual reduction of the prolapse combined with a purse-string suture, or surgical excision of the prolapsed portion of the urethra.