Laser treatment of urethral defects in geldings and stallions used as the primary treatment or in combination with a temporary subischial incision: Eight cases (2003–2011)

Two geldings with haematuria and 6 stallions with haemospermia presented for evaluation between 2003 and 2011 to the Iowa State University Lloyd Veterinary Medical Center. Both geldings presented for haemorrhage at the end of urination. All stallions presented for evaluation of infertility following natural service or artificial insemination that was related to haemospermia. Urethroscopy identified a urethral defect in all 8 horses. Both geldings possessed a urethral rent. One stallion possessed a urethral varicosity while the remaining 5 possessed a urethral rent. Two geldings and 2 stallions received only laser treatment. The remaining 4 stallions received concurrent laser treatment with a temporary subischial incision (TSI) into the corpus spongiosum penis. All 6 stallions received 8 weeks of sexual rest after the completion of the surgical/laser treatment. Laser treatment alone was successful in resolving haematuria in one of 2 geldings. In the stallion group, all 4 horses with a urethral rent receiving laser treatment concurrent with a TSI resolved haemospermia. Of the remaining stallions, one with a urethral varicosity resolved clinical signs with only laser treatment and one stallion with a urethral rent received only laser treatment and haemospermia recurred. We conclude that laser treatment of a urethral rent in geldings can result in resolution of haematuria. Laser treatment used in combination with a TSI may result in improved success when compared to surgery alone. Laser treatment alone can result in resolution of a urethral varicosity.     

Ulceration in the proximal portion of the urethra as a cause of hematuria in horses: four cases (1978-1985)

Sudden onset of hematuria was associated with mucosal ulceration of the proximal portion of the urethra in 1 stallion and 3 geldings. Hematuria was observed characteristically and consistently at the end of urination. Mucosal ulceration was identified endoscopically in the proximal portion of the urethra at the level of the ischial arch. Biopsy of an ulcerated area of the proximal urethra in one gelding revealed transitional cell carcinoma. Treatment regimens varied from systemic antimicrobial and/or vasoactive therapy to diversion of urinary flow via a temporary perineal urethrostomy. Hematuria resolved in 14 to 24 days (average, 20 days) after treatment was begun, except in one gelding that died of undetermined causes during an initial examination. In the 3 remaining horses, hematuria had not recurred for up to 9 years (average, 1 year).     

Squamous cell carcinoma of the equine external genitalia: a review and assessment of penile amputation and urethrostomy as a surgical treatment

A retrospective analysis was performed on 48 cases of suspected neoplasia involving the equine external genitalia. Forty nine squamous cell carcinomata (SCC) and 23 squamous papillomata (SP) were identified. Two cases of epithelial hyperplasia and one case of habronemiasis were also recognised histopathologically. The glans penis was the most common site of tumour development accounting for 53 per cent of cases of SCC and 61 per cent of SP. The urethral diverticulum, urethral process or urethra was involved in 27.6 per cent (8/29) of cases of SCC. Twelve per cent (5/41) of cases of SCC were confirmed to have metastatic involvement of the local lymph nodes. Papillomata showing pre-malignant changes were identified in five cases. Seventy five per cent (36/48) of the animals presented were ponies. All were geldings, mean age 16.5 years. Penile amputation and urethrostomy, preputial ablation and proximal urethrostomy or local excision were used in the surgical management of these animals; three cases were inoperable and destroyed at presentation. Oedema, haemorrhage and stenosis of the urethrostomy site were encountered as post operative complications. Sixty six per cent (6/9) of animals with SCC of the glans penis (without urethral involvement), which had a known history over the follow up period, treated by penile amputation and urethrostomy survived for longer than 18 months. Similarly, of those with urethral involvement only 28.6 per cent (2/7) survived for a similar follow-up period. SCC not uncommonly affects the external genitalia of aged pony geldings and frequently the glans penis. If the lesion is identified before local metastasis occurs, penile amputation and urethrostomy is indicated and the prognosis is favourable.     

Repair of urethral defects using fascia lata autografts in dogs

OBJECTIVE: To evaluate the feasibility of urethroplasty using a free fascia lata (FL) graft in the dog. STUDY DESIGN: In vivo experimental study. ANIMALS: Mixed-breed dogs (n=14). METHODS: Half of the circumference of the urethra, approximately 1.5 cm long, was excised in 14 male dogs to induce a urethral defect. FL (approximately 2 cm x 2 cm) harvested from the lateral thigh was sutured to the urethra using a 3-0 polyglactin 910 continuous pattern. Dogs were monitored daily for bladder distention and had urethral catheters until normal voiding was observed. On day 60, each dog had a positive contrast urethrogram, and then 8 dogs were euthanatized for gross and histologic examination. Six dogs were monitored for urologic problems for 6 months, and a positive contrast urethrogram was repeated. RESULTS: All dogs recovered successfully; 4 dogs had difficulty voiding for 2-3 days and urine was aspirated from these dogs every 3 hours until signs of painful urination disappeared. On positive contrast urethrograms, urethral anatomy was considered normal except in 4 dogs that had an irregular contour. Gross urethral examination confirmed an absence of ulceration, stricture, diverticula, or fistula formation, and the FL-lined graft survived in all dogs. No degenerative and reparative responses were observed. On histologic examination of the penile urethra, the lumen was intact, covered with transitional epithelium, and surrounded by corpus spongiosum with cavernous spaces and blood-filled vessels. CONCLUSIONS: Free FL grafts are incorporated satisfactorily and would appear to be useful for repairing urethral defects. CLINICAL RELEVANCE: FL grafts should be considered for repair of urethral defects in dogs.     

Catheter-induced urethral trauma in cats with urethral obstruction

Fifteen cats were evaluated with urethral obstruction. Penile trauma by catheterization was the major indication for perineal urethrostomy. Ten cats had developed a urethral stricture and five had rupture of the urethra following medical management. All cats had abnormalities in penis and/or prepuce and/or scrotal sacs including hyperemia or swelling. Perineal urethrostomy was performed in all cases and they were evaluated for 6 months after surgery. Few complications were noted. Urinary tract infection was the most frequent complication observed. The clients considered their cats to have a good quality of life following surgery.     

Ventral rupture of the penile tunica albuginea and urethra distal to the sigmoid flexure in a bull

A 4-year-old Limousin bull sustained a rupture of the ventral aspect of the tunica albuginea of the penis, 20 cm distal to the distal bend of the sigmoid flexure. The corpus spongiosum penis and urethra apparently ruptured at the same time.     

The effect of a surgically created shunt between the corpus cavernosum penis and corpus spongiosum penis of stallions on erectile and ejaculatory function

OBJECTIVE: To evaluate the effect of a shunt created between the corpus cavernosum penis (CCP) and corpus spongiosum penis (CSP) on erectile and ejaculatory function of normal stallions and to verify persistence of the shunt. STUDY DESIGN: The capability of stallions to develop an erection and to ejaculate was evaluated before and after creation of a corporeal shunt. Persistence of the shunt was determined by dye injection into the CCP at necropsy. ANIMALS: Six stallions. METHODS: A CCP-CSP shunt was created in five stallions. Semen was collected before and 4 to 14 weeks after surgery, before the horses were euthanatized. Dye was injected into the CCP to determine persistence of the shunt. Dye was also injected into the CCP of a control stallion. RESULTS: All stallions had normal erectile and ejaculatory function before and after surgery. Dye, injected into the CCP, entered the CSP in three of five treated stallions, demonstrating persistence of the shunt, whereas in two stallions, dye was found only in the CCP, indicating closure of the shunt. No dye was detected in the CSP of the control stallion. CONCLUSIONS: Creation of a corporeal shunt does not interfere with normal erection and ejaculation of stallions. Shunt closure is not necessary for stallions to retain normal erectile and ejaculatory function. CLINICAL RELEVANCE: Failure of a stallion affected by priapism to achieve normal erection or to ejaculate after creation of a corporeal shunt would likely be because of damage to corporeal tissue than from an effect of the shunt.     

Delayed urethral obstruction after uterine torsion in a pregnant dog

A 4 yr old pregnant female shih tzu was presented with abdominal discomfort and bloody vulvar discharge. The nongravid uterine horn was reflected caudally over the trigone, obstructing urine outflow. A cesarian section and ovariohysterectomy were performed. Postoperatively, the hematuria and pollakiuria resolved. Seventeen days later, the pelvic urethra was completely obstructed by a soft tissue mass that was identified by rectal palpation, blocked catheterization attempts, contrast radiography, ultrasonography, and surgery. Management included temporary cystostomy tube and definitive prepubic urethrostomy. Histologic diagnosis was severe, multifocal, necrosuppurative urethritis with fibroplasia, fibrosis, and cellulitis, apparently secondary to ischemia. Delayed urethral obstruction is a potential complication of canine uterine torsion.     

Cystoscopy

Cystoscopy is a diagnostic and therapeutic procedure commonly employed in human medicine but that has received limited application in small animal practice. Readily applicable, cost-effective instruments are available for use in the dog and cat. The urethral opening, urethra, bladder, and ureteral openings can be effectively assessed, and samples can be collected for histopathology, cultures, and stone analysis. Cystoscopy is indicated for assessment of chronic cystitis, hematuria, tenesmus, increased frequency of urination, urinary incontinence, alteration of urinary stream, trauma, and cystic and urethral calculi. Most cases can be evaluated transurethrally; the rest can be assessed by prepubic percutaneous cystoscopy.     

Priapism in the stallion

A review of the literature is given concerning the anatomy and pathophysiology of the equine penis with regard to priapism: a prolonged erection of the penis not associated with sexual arousal. Several treatment options, such as flushing of the corpus cavernosum penis with heparinized saline and the creation of shunt between the corpus cavernosum penis and the corpus spongiosum penis are discussed. Subsequently, a case of priapism in a stallion following the injection of acepromazine, is discussed. The priapism resolved after the corpus cavernosum penis was flushed with the stallion under general anaesthesia.     

Application of preputial tube-flap urethroplasty to establish a neourethra in a male dog with complications after preputial urethrostomy

A 14-year-old male poodle weighing 7.5 kg presented due to complications after preputial urethrostomy for management of preprostatic urethral rupture. Revision surgery was performed with preputial tube-flap urethroplasty via preputiotomy. A longitudinal flap was raised from the prepuce and anastomosed to the end of the previously cut urethra to create a neourethra and reduce tension at the urethrostomy site. Follow-up retrograde positive contrast urethrography performed 10 days and 6 months postoperatively showed no contrast leakage from either the neourethra tube flap or new preputial urethrostomy. A follow-up email questionnaire, based on the American Urological Association Symptom Index, was completed by the owner 6 months after surgery. The dog had excellent symptom scores, and urinated from the prepuce without difficulty in a manner resembling physiological urination.     

Ultrasonography and Surgical Treatment of an Unusual Case of Urethral Calculus in an Arabian Horse

This case report records an obstructive urolithiasis due to a large calcium carbonate urethral stone in an 11-year-old Arabian stallion. The stallion had colicky pain, anuria, and reduction in food and water intakes. Palpation of the penis revealed rhythmic contractions of the urethra, a hard mass in the penile urethra at the level of the ischial arch, and a dilated urethra proximal to the mass. Rectal examination revealed a distended and turgid urinary bladder. Passing a urethral catheter revealed a complete urethral obstruction at the level of the ischial arch. Ultrasonography revealed a calculus that appeared as an irregular, hyperechoic arch-like thick line with acoustic shadowing. Subischial urethrotomy was conducted under epidural anesthesia. Uneventful recovery was seen with no recurrence or complications for 12 months of available follow-up. In conclusion, clinical, rectal, and ultrasound examinations are valuable for definite diagnosis of urethral calculi in horses and the subischial urethrotomy appears to be successful in correcting this condition in horses.     

Subtotal penile amputation and preputial urethrostomy in a dog

CASE DESCRIPTION: A 6-year-old castrated male Shih Tzu was evaluated because of intermittent bleeding during urination. CLINICAL FINDINGS: Necrosis of the cranial portion of the penile shaft extended distally from the preputial fornix. Penile necrosis secondary to strangulation from paraphimosis was diagnosed. TREATMENT AND OUTCOME: A midline preputiotomy incision was used to expose the penile shaft; amputation was performed caudal to the preputial fornix. The terminal portion of the urethra was anastomosed to the preputial mucosa, which allowed the dog to urinate through the preputial orifice. CLINICAL RELEVANCE: Unlike the more conventional urethrostomy procedures performed in dogs, preputial urethrostomy eliminates the potential for local skin irritation during urination. Preputial urethrostomy is also easier to perform in those dogs in which penile amputation is required adjacent to the preputial fornix. A release incision cranial to the prepuce can be used to facilitate caudal displacement of the preputial mucosa, which facilitates urethral anastomosis to this structure. A midline preputiotomy incision provided excellent exposure of the penile shaft for this surgical procedure.     

Managing traumatic urethral injuries

Urethral injuries are relatively common in male dogs and cats. Urethral epithelium has impressive regenerative properties, and healing by second intention is effective as long as there is mucosal continuity across the traumatized area. Principles of managing traumatic urethral injuries include an accurate patient assessment, including a determination of the extent of the urethral injury; correction of electrolyte or acid-base disturbances; provision of urinary diversion, particularly with pelvic or perineal urethral defects; drainage of extravasated urine; and selection of a surgical procedure to repair or bypass the injured portion of urethra. Treatment options include temporary urinary diversion through cystostomy or urethral catheterization and second intention healing, permanent bypassing of the traumatized area through urethrostomy proximal to the injury site, and primary repair of transection injuries. The scrotal site is the most frequently used and preferred site for urethrostomy in the male dog to bypass the injured penile urethra. Urethral surgery necessitates care and attentiveness to detail, considering that accurate approximation of urethral mucosa minimizes fibrosis and helps maintain an adequate luminal diameter. Avoidance of stricture and preservation of function are goals of managing traumatic urethral injuries.     

Surgical procedure and postoperative management of a perineal urethrostomy in a chimpanzee (Pan troglodytes).

A chimpanzee (Pan troglodytes) with traumatic loss of the distal penis developed a gradually enlarging ventral urethral swelling and progressive dysuria. Endoscopy identified a urethral diverticulum, and endoscopic resection of the diverticulum wall was performed. Postoperative infection caused extensive necrosis of the penis, which necessitated a perineal urethrostomy. Complications of the urethrostomy included urethral obstruction from recurrent urethral stricture. The stricture was managed by regular dilatation using urethral bougies. Because of considerable postoperative swelling, catheterization was required to allow micturition following both the diverticular resection and polyp debulking. A shortened catheter sutured to the skin was tolerated for up to 10 days. Four yr after the urethrostomy, the animal is healthy and asymptomatic with endoscopic examinations performed at 12 mo intervals. This case demonstrates that with appropriate aftercare, perineal urethrostomy is an effective technique in the treatment of chronic distal urethral obstruction in the chimpanzee and probably other primate species.     

Traumatic urethral avulsion at the preputial fornix in a cat

A cat with pelvic fractures from being hit by a car had voided no urine in 13 hours despite iv administration of fluids. Abdominal radiography had revealed the pelvic fractures and apparently intact urinary bladder. Urine did not flow from a urethral catheter, and contrast radiography revealed the catheter to be extra-urethral within the penis. Intravenous pyelography revealed intact ureters and urinary bladder; celiotomy confirmed intact urinary bladder. Cystotomy and normograde urethral catheterization allowed localization of the ruptured urethra within the deep subcutaneous tissues of the caudal portion of the abdomen. After closure of the cystotomy and celiotomy incisions, perineal urethrostomy was performed.     

Urethrotomy and urethrostomy in the dog

An incision, or urethrotomy, is made into the urethral lumen to remove or relieve an obstruction temporarily. When permanent diversion of urine flow proximal to an obstructed, severely damaged, or diseased urethra is required, a urethrostomy is performed. Urethrostomy is also performed to diminish the risk of urethral obstruction due to recurrent urinary calculi that are not likely to be resolved with medical therapy. Whenever possible, to reduce the risk of urethral stricture or recurrent urinary tract infection, urethral surgery is avoided when an obstruction can be relieved by retrohydropropulsion or catheterization. Urethrotomy can be performed in the prescrotal or perineal regions depending on the level of the urethral obstruction. Although urethrostomy can be made in the perineal and antepubic positions, scrotal urethrostomy is the procedure of choice provided the lesion is distal to this area. Specific urethrotomy and urethrostomy procedures are described, including discussion about selection of the appropriate procedure for the urethral problem, patient stabilization considerations, general postoperative management, and risk of complications.     

Buccal mucosal graft urethroplasty for reversal of a perineal urethrostomy in a goat wether

OBJECTIVE: To describe the use of buccal mucosa as a urethral graft for reversal of perineal urethrostomy (PU) in a castrated male goat. STUDY DESIGN: Clinical case report. SAMPLE POPULATION: One client-owned castrated male goat. RESULTS: An 8-month-old Pygmy cross wether was admitted for urolithiasis and PU stricture. After repeated unsuccessful attempts at urethrostomy reversal and urethral reconstruction, a buccal mucosal graft was used for urethroplasty. Buccal mucosa proved to be an excellent graft for urethral repair. Normal urination has occurred through the reconstructed region for at least 24 months. CONCLUSIONS: Buccal mucosa worked well as a graft for urethroplasty and PU reversal. CLINICAL RELEVANCE: Grafting with buccal mucosa may also prove useful in other urethral repair techniques in small ruminants.     

Squamous cell carcinoma of the urethral process in a horse with hemospermia and self-mutilation behavior

A 14-year-old Arabian stallion was examined because of acute hemospermia. The stallion was used in an artificial breeding program and had a 6-year history of low-grade hemospermia and a 4-year history of self-mutilation behavior. During previous examinations, minor irritation of the urethral process was identified as the source of the bleeding. Physical examination revealed a mucosal ulceration in the distal portion of the urethra. Histologic examination of a biopsy specimen from this area revealed low-grade squamous cell carcinoma. The urethral process was excised, and the hemospermia resolved. Frequency of self-mutilation behaviors also decreased after surgery, suggesting that there may have been a link between irritation of the urethral process and development of self-mutilation behavior.     

Arginase alteration in the reproductive system of alloxan-diabetic dogs

This study was conducted to evaluate possible alteration in the activity of arginase, an important enzyme of cell proliferation and vascular smooth muscle contraction regulator in diabetics, that may be correlated with low fertility in diabetic patients. In this investigation, 6 apparently healthy adult male dogs were selected and divided in two groups, diabetics and non-diabetics. Diabetes mellitus was induced in one group by intravenous (IV) injection of alloxan (100 mg/kg). Dogs with a fasting blood glucose (FBS) of more than 200 mg/dl were considered to be diabetic. Four weeks following induction of diabetes mellitus, the animals in both groups were anesthetized by an IV injection of sodium thiopental. Livers and whole reproductive systems, including the testes, penis, urethra, and prostate, were dissected. The epididymides, corpus cavernosum, corpus spongiosum, penile urethra, and vas deferens were also dissected and removed from the reproductive system. Arginase activity and total protein were measured by the urea and Lowry's methods respectively in above mentioned sections. Plasma testosterone was determined by the radioimmunoassay method. The results showed significantly (P<0.05) increased arginase specific activity (ASA) in the liver, epididymis, prostate, corpus cavernosum and corpus spongiosum of the diabetic dogs. In the reproductive system of the diabetic dog, the maximum and minimum ASA was seen in the corpus cavernosum and testes, respectively (105.12 +/- 8.76 vs. 25.0 +/- 0.55). No such variation was observed in the ASA of normal dogs (39.0 +/- 5.47 vs. 25.0 +/- 5.47). There was no significant difference in plasma testosterone level between the groups. In conclusion, diabetes increased the ASA in liver, prostate, epididymis, corpora cavernosa, and corpora spongiosum of the male dogs and may contribute to erectile dysfunction or low fertility in diabetics.