Case selection and medical record information

Records (September 2011 through July 2024) of dogs with urethral prolapse admitted to our institution (The University of Florida Small Animal Teaching Hospital) were evaluated retrospectively. Inclusion criteria were (1) visual confirmation of a urethral prolapse on presentation; (2) surgical correction via UP, urethral RA, or CO₂ laser resection; and (3) a minimum 1-month follow-up documented at our institution or their referring veterinarian.

Data retrieved from the medical records included duration of clinical signs, age at initial surgery at our institution, neuter status, breed, weight, record of previous surgical intervention, documented signs of brachycephalic obstructive airway syndrome (BOAS), preoperative diagnostics, type of surgery, suture type and size, number of sutures used for UP, concurrent surgeries, postoperative care, and postoperative complications and treatments. Complications were designated as early if they occurred postoperatively before discharge, late if they occurred after discharge from the hospital, minor if they resolved with medical management, and major if they required mechanical revision (ie, surgical revision or dilations with urinary catheterization).

Population data, clinical signs, and diagnostic investigations

A total of 20 dogs met the inclusion criteria for this study. There was a median follow-up time of 5 months (range, 1 to 120 months). The follow-up included an evaluation and physical examination of the patient at our institution or by reviewing referring veterinarian records.

There were 9 neutered males and 11 intact males. One of the neutered males was neutered 5 days prior to presentation to the University of Florida; this dog had a urethral prolapse at the time of neuter, and a purse-string suture was placed. The affected breeds included English Bulldogs (n = 13 [65%]), American Pit Bull Terriers (n = 3 [15%]), a French Bulldog (n = 1 [5%]), a Labrador mix (n = 1 [5%]), a Miniature Dachshund (n = 1 [5%]), and a Miniature Pinscher (n = 1 [5%]). Of these dogs, 16 of 20 (80%) were either a brachycephalic breed (English Bulldog or French Bulldog) or had documented signs of BOAS at initial presentation (2 American Pit Bull Terriers). Documented signs in the American Pit Bull Terriers included an elongated soft palate (n = 2 [100%]), stenotic nares (n = 1 [50%]), macroglossia (n = 1 [50%]), and everted saccules (n = 1 [50%]). The median age at presentation was 12 months, with a range of 6 months to 180 months. The median bodyweight was 22.1 kg, with a range of 7.8 kg to 39.4 kg.

Prior surgical intervention was documented in 5 of 20 cases (25%), including 1 UP, 1 RA, 1 purse-string suture, and 2 unknown procedures. The most common presenting complaints included bleeding from the prepuce (n = 13 [65%]), urethral prolapse characterized by visible everted urethral mucosa (n = 6 [30%]), or a combination of bleeding and visible prolapse (n = 1 [5%]). The median duration of clinical signs prior to presentation was 4 days, with a range from 1 to 280 days. Clinical signs of urogenital disease documented on presentation included visible urethral prolapse (n = 20 [100%]), urethral prolapse with concurrent bleeding from the penis (n = 7 [35%]), unilateral cryptorchid (n = 1 [5%]), enlarged prostate (n = 1 [5%]), and a papillomatous mass at the base of the penis (n = 1 [5%]). Nine dogs (45%) had signs of BOAS documented on either physical examination or upper airway examination, including elongated soft palate (n = 6 [67%]), stenotic nares (n = 5 [56%]), everted laryngeal saccules (n = 2 [22%]), everted tonsils (n = 1 [11%]), collapse of the cuneiform process (n = 1 [11%]), stertorous breathing (n = 1 [11%]), increased respiratory effort (n = 1 [11%]), and macroglossia (n = 1 [11%]). Previous corrective airway surgery had been performed in 2 dogs.

Preoperative urinalysis was performed in 10 dogs (50%). Hematuria (n = 2 [20%]), bacteriuria (n = 2 [20%]), pyuria (n = 1 [10%]), and crystalluria (n = 1 [10%]) were identified in 6 dogs. Four of the urinalyses revealed no abnormalities. Diagnostic imaging prior to surgery was performed in 12 dogs. Thoracic radiograph (n = 7) findings included congenital vertebral anomalies (n = 6 [86%]), severely thickened and elongated soft palate (n = 3 [43%]), tracheal hypoplasia (n = 1 [14%]), vertically oriented hyoid apparatus (n = 2 [29%]), and cranial mediastinal soft tissue opacity (n = 2 [29%]). There was no documentation of hiatal hernia or aspiration pneumonia within these 7 dogs. Abdominal radiographs (n = 5) revealed similar vertebral abnormalities, with no evidence of hiatal hernia or urinary calculi. One dog had chronic malunion of pelvic fractures with moderate displacement and narrowing of the pelvic canal. Urinary bladder debris (n = 3 [60%]), prostatomegaly (n = 2 [40%]), cystolithiasis (n = 1 [20%]), and cryptorchid inguinal testicle (n = 1 [20%]) were identified via abdominal ultrasound in 5 dogs. One dog had CT of the head, which revealed relative macroglossia, thickened and elongated soft palate, tympanic bullae thickening, aberrant caudal nasal turbinates, and hemivertebrae with associated kyphosis.

Surgical procedures

Urethropexy was performed in 6 dogs (30%), RA in 10 dogs (50%), and CO₂ laser resection in 4 dogs (20%). All UP procedures were completed with 2-0 (n = 3 [50%]) or 3-0 polydioxanone (Ethicon; n = 3 [50%]) in a horizontal mattress (n = 1 [17%]) or simple interrupted pattern (n = 5 [83%]). The median number of interrupted sutures placed during UP was 3.5 (range, 3 to 4). The suture type for RA varied between polydioxanone (n = 1 [10%]), glycomer 631 (Biosyn; Medtronic; n = 6 [60%]), polyglactin 910 (Vicryl; Ethicon; n = 2 [20%]), and poliglecaprone 25 (Monocryl; Ethicon; n = 1 [10%]), with sizes ranging from 4-0 to 6-0. The most common suture pattern for RA was a simple interrupted pattern (n = 6 [60%]), followed by a simple continuous pattern (n = 4 [40%]). One dog with a simple interrupted pattern also had 1 horizontal mattress suture placed (n = 1 [17%]).

For the CO₂ laser procedure, the penis was manually extruded from the prepuce and maintained in this position using a Penrose drain (Cardinal Health) tourniquet placed at its base. A chilled red rubber catheter was introduced retrograde into the urethral orifice while the prolapsed tissue was held with DeBakey forceps. The red rubber was passed to the distal aspect of the os penis. A CO₂ laser (LuxarCare LLC) was used to resect the nonviable, distal urethral tissue. Three dogs that underwent surgical resection via CO₂ laser (75%) did not require any sutures. One CO₂ dog had continued hemorrhage and prolapse (25%), which led to an RA during the same anesthetic event. This dog had 6 horizontal mattress sutures of 5-0 Biosyn placed circumferentially.

Concurrent procedures were performed in 15 dogs, which included airway surgery (n = 4 [27%]), neuter (n = 10 [67%]), mass removal (n = 1 [7%]), and bilateral anal gland flushing (n = 1 [7%]). Median surgical time was 60 minutes (range, 10 to 130 minutes). Staphylectomy was performed in all 4 dogs that underwent airway surgery, and 2 dogs also had an alar wedge resection. Histopathology of the resected urethral mucosa was performed in 4 dogs. Ulcerative, necrotizing urethritis was diagnosed in 2 dogs (n = 2 [50%]), squamous epithelial hyperplasia with ballooning degeneration and multifocal erosions was diagnosed in 1 dog (n = 1 [25%]), and 1 dog was diagnosed with transitional cell carcinoma (n = 1 [25%]).

Outcomes and complications

Early minor complications occurred in 13 of 20 dogs (65%) and were documented in 3 of 6 UP cases (50%), 6 of 10 RA cases (60%), and 4 of 4 CO₂ cases (100%; Table 1). These complications included mild hemorrhage (n = 8), mild swelling of the distal penis (n = 5), and stranguria (n = 1). Early major complications occurred in 1 dog (5%), who received CO₂ laser resection. This complication was defined as persistent urethral prolapse during the procedure, which was revised during the same anesthetic event with an RA. There were no early major complications in the UP or RA groups.

Late minor complications occurred in 9 of 20 dogs (45%) and were documented in 1 of 6 UP cases (17%), 7 of 10 RA cases (70%), and 1 of 4 CO₂ cases (25%; Table 1). These complications included hematuria (n = 6), minor recurrence of urethral prolapse that did not require revision (n = 2), pollakiuria (n = 2), and stranguria and ureteritis (n = 1). Late major complications occurred in 7 of 20 dogs (35%) and were documented in 3 of 6 UP cases (50%) and 4 of 4 CO₂ cases (100%). There were no late major complications in the RA group. These complications included recurrence of urethral prolapse (n = 4) and urethral strictures (n = 3).

The recurrence of urethral prolapse occurred in 6 of 20 dogs (30%), including 3 dogs that underwent UP (3 of 6 [50%]), 2 dogs that underwent RA (2 of 10 [20%]), and 1 dog that underwent CO₂ (1 of 4 [25%]; Table 2). The time to recurrence after hospital discharge was not defined. However, the time from first surgery to return for recurrence was shortest in the CO₂ group (6 days), followed by the RA group (median, 10 days; range, 9 to 11 days), and finally the UP group (median, 315 days; range, 288 to 412 days). All dogs that had recurrence within the UP and CO₂ groups required 1 or more revision surgeries. The 2 dogs with recurrence in the RA group were deemed minor and were treated with medical management (trazodone, acepromazine, and carprofen). In 1 of these cases, the prolapse would self-resolve when the dog calmed down. In the other case, the prolapse was only approximately 20% of the original size and not causing any clinical signs. Therefore, revision was not required in either of these cases. The initial revision surgery was an RA in 3 cases and a phallectomy and scrotal urethrostomy in 1 case. Of the 4 cases that required revision surgery, 2 had repeat recurrence of urethral prolapse.

The CO₂ group had 2 major complications identified: urethral stricture and recurrence of urethral prolapse (Table 1). Of the 4 cases, 1 had only urethral stricture, 1 had only recurrence of urethral prolapse, and 2 had urethral stricture followed by urethral prolapse after stricture treatment. The median time to urethral stricture was 8 days (range, 3 to 10 days). In the case with only a urethral stricture, the stricture was treated successfully with a combination of prednisolone at an anti-inflammatory dose (0.5 to 1 mg/kg/d), amoxicillin (16 mg/kg, q 12 h), and serial dilation via urinary catheterization. The case with just recurrence of urethral prolapse was revised with an RA (Table 2). Urethral prolapse occurred again 226 days after the revision RA. A third surgery was not pursued due to a lack of clinical signs in this dog. One dog in the CO₂ group developed recurrent urethral strictures starting 8 days postoperatively. An attempt was made to dilate via urinary catheterization, but ultimately a penile wedge resection was pursued 82 days after the initial surgery. Fifteen days after the penile wedge resection, recurrent urethral prolapse was diagnosed and revised via RA. The final dog in the CO₂ group developed a urethral stricture 3 days postoperatively. Notably, this patient had excessive hemorrhage and persistent prolapsing during the initial surgical procedure, and so an RA was performed during the same anesthetic event. Urethral stricture was not able to be resolved with dilation via urinary catheterization, and so a partial penile amputation was performed. Urethral prolapse occurred 11 days after that and revised via RA.

In the 7 cases with major complications (Table 1), 5 (71%) had other concurrent procedures under the same episode of general anesthesia, including neuter (n = 3) and corrective airway surgery (n = 2). The median surgical time for these 7 cases was 60 minutes (range, 45 to 90 minutes). Seven of 16 brachycephalic dogs had major complications (43.8%), and 0 of 4 nonbrachycephalic dogs had major complications (0%). Of the 4 brachycephalic dogs that underwent concurrent airway surgery, 2 had major complications (50%), and 2 did not (50%). Of the 12 brachycephalic dogs that did not undergo concurrent airway surgery, 5 had major complications (41.7%), and 7 did not (58.3%; Table 3). Four of the 7 dogs with major complications (57%) were intact on presentation. Recurrence was noted in 4 of 9 castrated male dogs (44%) and 2 of 11 intact male dogs (18%).