Introduction

Pseudohermaphrodite and intersex are interchangeable terms to describe individuals possessing characteristics of both sexes, usually presenting with ambiguous external genitalia and gonadal tissue of a single or both sexes.¹ In this instance, the dog presented with abnormal male external genitalia, with an entire female internal reproductive tract and female gonads, classifying this dog as a female pseudohermaphrodite. This report describes the presentation, treatment, and outcome in a case of persistent urinary incontinence due to a naturally occurring congenital urethrovaginal fistula (UVF) with blind-ending vagina in a female pseudohermaphrodite dog. No cytogenetic analysis was performed on this dog to determine the karyotype; however, histopathological analysis of the resected tissue confirmed ovarian tissue and absence of testicular tissue.

Case Report

An 8 mo old 27 kg male Doberman pinscher was presented to the Hospital for Small Animals for investigation and treatment of persistent urinary incontinence. The owner reported difficulty house-training and a 3 mo history of notable incontinence with increasing severity and hematuria in the 2 wk before the referral. Multiple courses of empirical antibiotics had been prescribed in the absence of urine culture within that period with no resolution of clinical signs. No investigations or additional drug trials had been performed before the referral because of financial limitations. On examination, the dog had continuous urine leakage and abnormal external genitalia. In particular, the author observed a micropenis and the absence of a scrotum and testes. Hematology, biochemistry, and urine analysis and culture were unremarkable. An abdominal computed tomography (CT) scan was performed; the patient was under general anesthesia and positioned in sternal recumbency. A 64-row multidetector CT scanner^a was used with pre- and postapplication of iodinated nonionic contrast medium^b injected IV at a dose of 2 mL/kg. The injection of contrast medium was followed by the injection of 10 mL of saline solution. Subsequently, a retrograde urethrogram was performed with the use of a 6-French rigid urinary catheter. A total of 27 mL (1.0 mL/kg) of non-diluted contrast medium was injected in the urethra.

CT images were reviewed using a DICOM viewer^c. A large fluid-filled cavity (Hounsfield unit 16) was visible, extending from the most caudoventral aspect of the abdomen to the level of the fourth lumbar vertebra. The fluid-filled cavity created a mass effect in the caudal abdomen by displacing dorsally the colon and cranially the small intestine. A small fluid-filled cavity was seen cranial to it, most likely representing the urinary bladder. On postcontrast CT images, no enhancement of the fluid-filled cavity was seen, and both ureters were visible with no signs of ectopia detected. Additionally, there were no visible retained testicles in the abdomen or inguinal region and no uterus or ovaries detected in the peritoneal cavity.

On retrograde urethrogram study (Figure 1), contrast medium was seen filling the urethra and the urinary bladder, which was markedly displaced cranially. A small amount of contrast medium was also seen within the anomalous fluid-filled cavity. Additionally, a small, linear, contrast-enhancing structure was visible cranial to the pubic brim, connecting the urethra to the fluid filled cavity (Figure 1, white arrow). The main differential diagnosis at this stage was a persistent Mullerian duct with urethral communication.

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Based on the imaging findings, surgical exploration was recommended with the view of removing the anomalous fluid-filled structure communicating with the urethra and a gonadectomy, under the presumption there may be retained testicles. The patient was anesthetized and positioned in dorsal recumbency; the abdomen was clipped and aseptically prepared. The abdomen was entered through a midline celiotomy from the umbilicus to the pubis.

Exploration revealed that the large fluid-filled cystic structure seen on CT was consistent with a vagina. There was also a complete uterus joined with the cervix and ovaries sitting in the physiologically anatomical location (Figure 2A). A 6-French rigid urinary catheter was passed through the penile orifice into the bladder, and a sample of urine was collected for culture and sensitivity. On compression of the bladder, the vagina filled with urine. Careful retraction of the uterus in a cranioventral direction highlighted a communication between the vagina and proximal urethra just cranial to the pubic brim close to the level of a hypoplastic prostate.

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The blind-ended vagina terminated ∼3 cm caudal to the urethrovaginal communication. The ventral vaginal wall was adherent to the body and neck of the urinary bladder while dorsally it was adherent to the ventral descending colon (Figure 2B). The UVF extended from the ventral caudal vagina to the dorsal proximal urethra. After careful dissection, the aberrant communication could be isolated and transected, allowing for the removal of the reproductive tracts and gonads en bloc. A blood vessel sealing device^d was used to seal and transect the ovarian pedicles and uterine ligaments bilaterally, and the cervix and vagina were double ligated using 2-0 polydioxanone suture before removal. The UVF was dissected and excised, leaving a defect in the dorsolateral urethral wall requiring reconstruction. Closure of the defect was completed using 4-0 polydioxanone in a simple continuous pattern, reinforced by simple interrupted sutures, and the urethral lumen was maintained with the previously placed urinary catheter. The urinary bladder was filled with saline (0.9% NaCl) via the catheter, and gentle compression on the bladder confirmed absence of urine leakage at the urethral site. Once complete reconstruction of the communication was achieved, the site was patched with omentum to facilitate healing. The remainder of the abdomen was explored, and no other apparent gross anomalies were identified. The rigid urinary catheter was replaced with an indwelling 6-French Mila urinary catheter toward the end of surgery. This was intended to stay in place throughout the recovery period in order to facilitate regeneration of the urothelium and to support urethral healing. The abdomen was closed routinely, and the entire reproductive tract was submitted for histopathology.

The patient recovered uneventfully from anesthesia, and an abdominal point-of-care-ultrasonography was performed at 24, 48, and 72 hr after the operation. Initially, a small amount of free fluid was detected in the caudal abdomen at the level of the urethral reconstruction site. This free fluid had complete resolution by the 72 hr mark.

Amoxicillin-clavulanic acid was started perioperatively as prophylaxis at a dose of 20 mg/kg IV q 8 hr, then was continued orally at the equivalent dose for 5 days after surgery. A urine culture and sensitivity sample obtained at the time of surgery grew Klebsiella spp., which was sensitive to the above antimicrobials. The patient received 0.2 mg/kg methadone intravenously q 4 hr for 24 hr following surgery and 0.2 mg/kg meloxicam IV as a single dose at the time of surgery followed by a 25 kg dose q 24 hr orally for 14 days after the operation. The dog also received 250 mg acetaminophen orally q 8 hr for 14 days after the operation. The dog remained hospitalized for 7 days, with the indwelling urinary catheter being in place for 4 days. Following removal of the urinary catheter, the patient was closely monitored for signs of uroabdomen. Over the following 48–76 hr, the patient actively passed large amounts of normal urine with the absence of stranguria and hematuria. There was no apparent urine leakage, and continence was assumed.

Four days after discharge, urine dribbling and stranguria were reported. A free-catch urine sample was obtained, and culture was positive, with sensitivity to all antimicrobials tested. The dog was prescribed oral amoxicillin-clavulanic acid for a further 14 days, and clinical signs improved over the following days and again fully resolved. Six months after the operation, the dog is reportedly doing well with no recurrence of urinary incontinence and no further urinary tract infections. Histopathology confirmed tissue consistent with that of a vagina, cervix, uterus, and ovaries.

Discussion

To the authors’ knowledge, this is the first case of persistent urinary incontinence due to a naturally occurring congenital UVF with blind-ending vagina in a female pseudohermaphrodite dog to be reported. Intersex animals are often associated with complex urogenital abnormalities, including urogenital fistulae, occurring as a result of abnormal embryological sexual development. Although rarely reported, these abnormalities are usually well recognized on the basis of abnormal external genitalia or sexual development. These disorders, termed disorders of sexual development, have repeatedly been linked with urinary incontinence and recurrent urinary tract infections in canine reports.² Urethrovestibular, vestibuloperineal, vesicovaginal, ureterovaginal, and urethrorectal fistulas have all been reported in domestic canines and have clinically been associated with urinary incontinence and recurrent urinary tract infections.^3–8 It is proposed that, in cases with a UVF, incontinence may result from the reflux of urine into the vagina during micturition followed by passive leakage into the urethra from this vaginal reservoir.⁶ Vesicovaginal fistulas are the most common type of urogenital fistula in women, and they are often secondary to prolonged labor or as a complication of laparoscopic hysterectomy.⁹ In a review of congenital urogenital fistulas in humans, 37 cases were identified. Of these, 30 were vesicovaginal, 6 were uterovesical, and only 1 was a UVF.¹⁰ UVFs are almost always acquired in women as a consequence of traumatic parturition and previous vaginal surgeries.¹¹ This etiology differs from those cases described in veterinary literature, in which most cases are assumed to be congenital in young animals.⁶ A unique case report describes the development of a UVF in a 1 yr old dog, secondary to a migrating grass awn.¹²

In a review of cases of canine disorders of urination associated with intersexuality, Holt et al. reviewed nine cases between 1965 and 1982, age range from 3 wk to 6 yr, in which the vagina terminated in the pelvic portion of the urethra.⁶ Two cases were euthanized on diagnosis, seven cases had gonadectomy, two of these also had obliteration of the urethrovaginal communication, and overall only three cases had a reported good outcome for an unknown duration. All cases had some phenotypical signs of inter-sexuality; however, only a single case was suspected to be a pseudohermaphrodite.¹³ Additionally, a recent report describes a 3 yr old intersex dog with an anomalous connection between a remnant uterus and vagina and the pelvic urethra, which was removed surgically, resulting in resolution of incontinence.¹⁴ Our report differs from the above because the vagina terminated blindly and the communication joined the urethra cranial to the pelvic brim and thus not within the pelvic portion of the urethra.

The clinical presentation of UVFs in women depend on the location and the size of the communication. Some individuals can be continent and often minimally symptomatic if the fistula is located in the distal third of the urethra and some show intermittent positional urinary incontinence if the fistula is located in the middle or proximal urethra.¹¹ In dogs with urogenital fistulae, significant urinary incontinence is commonly the primary reason for veterinary consultation. Women with UVFs are also commonly found to have recurrent urinary tract infections.¹¹ In the patient, urine cultured from the initial consultation was negative; however, urine cultured positive at the time of surgery and again in the postoperative period after the initial course of antibiotics. The positive culture, at the time of surgery and in the postoperative period, is assumed to be a result of frequent catheterization of the urethra during diagnosis and the use of an indwelling urinary catheter after the operation, despite adhering to daily catheter care protocols. Additionally, it is important to note that the subsequent culture-positive urine sample obtained 4 days after the patient was discharged from hospital was collected using a “free-catch” technique, in which there could have been bacterial contamination from the penile urethra. The reason for this is that the referring veterinarian did not feel comfortable performing a cystocentesis, which would have been the gold-standard way of obtaining this sample in this particular patient after the operation.

That being said, this finding in women could suggest that dogs with UVFs may be predisposed to recurrent urinary tract infections, and although not supported by this case, these patients may benefit from long-term monitoring.

Additionally, it was assumed that the hematuria observed in lead up to referral was resulting from an undiagnosed urinary tract infection; however, on diagnosing this animal with pseudohermaphroditism, it could be hypothesized that the hematuria may have been associated with the hormonal effects of estrus.

In humans, cystourethroscopy helps to characterize the location and size of the fistula.¹⁵ Abdominal ultrasonography, CT, and MRI have also been described in the diagnostic workup for urogenital fistulae in dogs.^3,7,14 Classically, an abdominal ultrasound would have been performed as part of our investigations into urinary incontinence. However, because of financial limitations, diagnostic imaging was limited to CT scan and retrograde urethrogram only in this dog, in hope it would yield the most information. On reflection of this particular case, we believe a retrograde urethrogram may have been enough for us to identify the fistula and prompt surgical exploration. The scan failed to identify the ovaries with entire female reproductive tract but did identify a small communication between the urethra and a fluid-filled cystic structure, which was suspected to be a persistent Mullerian duct. The inability of CT to identify the reproductive tract was most likely because of the large fluid-filled structure creating a mass effect with displacement of the adjacent organs. In retrospect, the uterus was suspected to be compressed by the colon, and the fluid-filled cavity and the ovaries were likely displaced cranially by the small intestine. Because this differed from what was seen intraoperatively, combining CT scan with urethrocystoscopy or abdominal ultrasonography may have been beneficial in preoperative diagnosis. Urethroscopy may have allowed visualization of the preprostatic urethral defect, and abdominal ultrasound may have localized the intraabdominal ovaries. Vaginoscopy and urethroscopy may be feasible and beneficial in those cases presenting with an external vulva. However, in those cases with external penile urethras, urethroscopy would not be possible because of the length and small diameter of the urethra. In this dog, the CT scan identified the abnormal aberrant communication but surgical exploration was the key in diagnosing the UVF and the presence of the female reproductive tract. An interesting point in this case was that the micropenis went unnoticed by the referring veterinarian and owner, and the absence of a scrotum and testes was assumed to be due to cryptorchidism. This suggests that subtle external abnormalities, which may typically be observed casually, could be associated with pseudohermaphroditism.

In human medicine, no standardized guidelines on treatment of UVFs have been established because of the infrequency of the condition, and thus, they tend to be addressed on a case-by-case basis. In a study of 71 women, 90% of fistulas were definitively closed after a single surgery.¹¹ Stress urinary incontinence was the most common postoperative complication, which was seen in 52% of women. This was proposed to be due to reduced urethral elasticity and mobility following repair.¹¹ In this case, surgical gonadectomy and urethral reconstruction resulted in resolution of urinary incontinence. Six months after the operation, the owner reports the dog is clinically well with no recurrence and no medium- to long-term surgical complications.

Conclusion

This report describes a young female pseudohermaphrodite canine with persistent urinary incontinence as a result of a naturally occurring congenital UVF. CT scan allowed identification of a urethral fistula, but explorative surgery was required for diagnosis of the UVF. Isolation and reconstruction of the urethra was challenging, but surgical gonad hysterectomy and urethral reconstruction was done successfully by a skilled surgeon, and the patient recovered uneventfully. UVF and pseudohermaphroditism should be considered in young animals with persistent urinary incontinence even with very subtle abnormalities in the external genitalia, and diagnosis may be supported using retrograde urethrogram or CT and explorative laparotomy. Surgical intervention should be considered in animals with similar presentations with a good medium-term outcome and resolution of clinical signs.