Prostatopexy as a treatment for urethral sphincter mechanism incompetence in male dogs

OBJECTIVES: The incidence of urinary incontinence due to urethral sphincter mechanism incompetence (USMI) in male dogs is relatively rare compared with the incidence in bitches, but the medical management of USMI in male dogs is less rewarding than in bitches. Attempts have been made to manage this condition surgically using either urethral bulking agents such as Teflon or by relocating the intrapelvic bladder neck to an intra-abdominal position by vas deferentopexy. This paper reports the response to prostatopexy in male dogs with USMI. METHODS: The response to prostatopexy was determined in nine severely incontinent male dogs with USMI that were followed up for periods ranging from 10 months to five years (mean 2.3 years). RESULTS: One dog was cured, four were improved, and no improvement in the frequency or degree of urinary incontinence occurred in the remaining four animals. No complications were seen in any of the dogs. CLINICAL SIGNIFICANCE: Prostatopexy may provide a further method of treating male dogs with USMI that do not respond to medical therapy.     

Static hydraulic urethral sphincter for treatment of urethral sphincter mechanism incompetence in 11 dogs

Objective : To review the postoperative results and complications associated with urethral sphincter mechanism incompetence managed with a static hydraulic urethral sphincter. Methods : Case records and a telephone owner questionnaire were retrospectively used to assess postoperative urinary continence scores (1 – dripping constantly to 10 – completely dry) and presence and frequency of complications. Results : Eleven spayed females were included. Median continence score/10 (range) awarded preoperatively was 3 (2 to 6), and scores at two weeks, three and six months were 8 (4 to 10), 9 (4 to 10) and 8 (4 to 10), respectively. At the last survey, the median continence score of 9 (5 to 10) was significantly better (P=0·004) than before surgery. Complete continence was achieved in 36·4% of dogs. The median (range) follow‐up time was 412 (118 to 749) days. Complications occurred in 9 of 11 dogs and included dysuria (n=7), bacterial cystitis (n=7), longer urination time (n=8), urinary retention (n=3), haematuria (n=1), pain (n=3) and incisional seroma (n=3). Clinical Significance : Static hydraulic urethral sphincter was frequently associated with minor complications but no major complications (i.e. those requiring further surgery). Continence scores were significantly improved compared with those before surgery, with the possibility of further improvement following inflation of the sphincter.     

Urethral sphincter mechanism incompetence in the male dog: importance of bladder neck position, proximal urethral length and castration

The radiographs of 37 incontinent adult male dogs with urethral sphincter mechanism incompetence were compared with those of 28 control dogs to determine if, as in the bitch, differences in bladder neck position and urethral length were implicated in the pathophysiology of urethral sphincter mechanism incompetence. Bladder neck position was significantly different; compared with continent dogs, incontinent animals were significantly more likely (P<0.005) to have intrapelvic than intra-abdominal bladder necks. However, after allowing for the influence of body size, and unlike the situation in the bitch, there was no significant difference in proximal urethral length between the two groups. Bladder neck position was significantly related to prostate size (P<0.001) and it is suggested that this is one reason why castrated male dogs are more prone to urethral sphincter mechanism incompetence than entire animals. A logistic regression analysis revealed that both bladder neck position and castration status were significant risk factors for incontinence and that they appeared to be acting independently of each other.     

Treatment of urethral sphincter mechanism incompetence in 11 bitches with a sustained-release formulation of phenylpropanolamine hydrochloride

Between 1995 and 1999, urethral sphincter mechanism incompetence was diagnosed in 11 bitches. They had been treated with phenylpropanolamine hydrochloride at the recommended dose rate, but had shown no response or had become refractory to treatment. They were treated with phenylpropanolamine hydrochloride in a sustained-release formulation combined with diphenylpyraline hydrochloride. The urinary incontinence resolved fully in six of the bitches, two of which remained continent after the treatment was withdrawn; two showed a marked improvement on daily treatment, but the other three bitches failed to respond and underwent colposuspension.     

Urethropexy for the management of urethral sphincter mechanism incompetence in the bitch

Urethropexy was performed on 100 bitches for the management of urethral sphincter mechanism incompetence (SMI). The dogs ranged in age from 12 months to nine years (mean 4.5 years). Diagnosis of the condition was based upon clinical, laboratory and contrast radiographic examinations, and clinical response to medical management. In all bitches, incontinence developed in the adult individual and in the majority (89 bitches) after spaying. Radiographic findings were unremarkable in 22 bitches, apart from the presence of an intrapelvic bladder neck. Follow-up periods ranged from 12 months to seven years (mean 2.9 years). Fifty-six bitches were completely cured by surgery, 27 became less incontinent and 17 either failed to respond (nine animals) or showed an initial improvement in urinary function, but then relapsed (eight animals). Nine of these 17 animals underwent a second urethropexy procedure, resulting in a cure in six and an improvement in three cases (follow-up 12 to 41 months, mean 22.2 months). A deterioration in the response rate was observed over time. Postoperative complications were seen in 21 bitches and included an increased frequency of micturition (14 bitches), dysuria (six bitches) and anuria (three bitches).     

Long term use of hydraulic artificial urethral sphincters in nine dogs from New Zealand with urethral sphincter mechanism incompetence

AIMS: To report on the long-term outcomes of hydraulic artificial urethral sphincter (HAUS) placement for the correction of urethral sphincter mechanism incompetence (USMI) in New Zealand dogs.

METHODS: Retrospective data were obtained from cases of dogs which had a HAUS placed after failed medical and/or surgical management of USMI between August 2012 and November 2016. Owner assessment of urinary incontinence was evaluated by an online survey in May 2017 using a visual analogue scale (0 being normal, 100 being severely affected) for the frequency, volume and severity of any straining to urinate, immediately prior to the placement of the HAUS and at the time of the survey. The number of days between surgery and the completion of survey were recorded.

RESULTS: Seven females and two male dogs, which were all desexed except for one female, were eligible for inclusion in the study. The period of follow-up following HAUS placement ranged from 206–1,685 days. Following HAUS placement, frequency and volume of urinary incontinence decreased for six dogs and were practically unchanged for three dogs. The median frequency score decreased from 70 to 13 and the volume score decreased from 73 to 12. There was no consistent change in the perceived degree of straining to urinate. Complications occurred in three dogs; one required repositioning of a dislodged injection port, one required management for haematuria and a hypoplastic bladder, and one required surgical removal of fibrous tissue around the HAUS cuff.

CONCLUSIONS AND CLINICAL RELEVENCE: HAUS placement was an effective method for the treatment of persistent USMI in most dogs and provided good clinical results based on owner assessment. The technique was associated with few complications and allowed successful long-term control of urinary incontinence without the need for medical management.     

Evaluation of phenylpropanolamine in the treatment of urethral sphincter mechanism incompetence in the bitch

In a multicentre, blinded, placebo-controlled trial, 50 dogs were treated for 28 days with either phenylpropanolamine or a placebo control. Each was given at a dose of one drop per 2 kg orally three times daily, equivalent to 1 mg/kg three times daily of phenylpropanolamine. Dogs that presented with clinical signs consistent with urinary sphincter mechanism incontinence were included in the study. They were examined on three occasions by the investigating veterinary surgeon. The frequency and volume of unconscious urination were scored by veterinary surgeons according to a pre-established scoring system. Phenylpropanolamine proved to be more effective than the placebo in regard to several parameters. At day 28, 85.7 per cent of phenylpropanolamine-treated cases had no episodes of unconscious urination compared with 33.3 per cent of placebo-treated cases. This was statistically significant. Few, mild side effects were seen in either group.     

Ureteral ectopia and urethral sphincter mechanism incompetence: an update on diagnosis and management options

The two leading causes of urinary incontinence in dogs are ureteral ectopia in juveniles and urethral sphincter mechanism incompetence in adults. While the accuracy of diagnosis of ectopic ureters has improved due to increased use of CT and/or cystoscopy, the diagnosis of urethral sphincter mechanism incompetence largely remains one of exclusion. New treatment options have been developed for both conditions, which have reduced morbidity and mortality, although the rate of long‐term urinary continence has not significantly improved for either and neither has our understanding of the pathophysiology behind these failures. This review provides updates on the management of both of these conditions, with discussion of controversial areas and thoughts for future directions.     

Clinical evaluation of a single daily dose of phenylpropanolamine in the treatment of urethral sphincter mechanism incompetence in the bitch

The objective of this retrospective study was to determine the efficacy of a single daily oral dose of phenylpropanolamine (PPA) in the treatment of urethral sphincter mechanism incompetence (USMI) in bitches. Nine bitches diagnosed with USMI were treated with a single daily dose [1.5 mg/kg body weight (BW)] of PPA for at least 1 month. Urethral pressure profiles (UPP) were performed in 7 dogs before treatment and repeated in 4 of them after treatment. Treatment with PPA resulted in long-term continence in 8/9 bitches. One dog did not respond to PPA and was treated surgically later. Recheck UPPs showed a significant increase in maximal urethral closure pressure in the 4 bitches after treatment with PPA compared to before treatment. In conclusion, long-term continence can be achieved in bitches affected with USMI after administration of a single daily dose of PPA (1.5 mg/kg BW).     

Semitendinosus muscle transfer flap for external anal sphincter incompetence in a dog

A 5-year-old sexually intact female Yorkshire Terrier was referred with a history of fecal incontinence of at least 2 years and chronic intermittent colitis. The external anal sphincter to the left of the anus was intact; the external anal sphincter was not detectable to the right of the anus. To repair the defect, the semitendinosus muscle was isolated and severed 2 cm proximal to its insertion on the tibia. Care was taken to preserve the integrity of the vasculature and nerve supply in the proximal third of the muscle body. The body of the muscle was passed around the ventral and right aspects of the rectum; the cut end was secured with simple interrupted sutures dorsal to the levator ani and coccygeus muscles to simulate the external anal sphincter. After surgery, the dog could defecate normally. Absence of a portion of the external anal sphincter may be congenital or the result of anorectal trauma, rectal prolapse, severe perineal disease, or surgical resection. The use of a semitendinosus muscle flap for treatment of fecal incontinence secondary to sphincter incompetence in dogs may be a viable alternative to euthanasia.     

Phenylpropanolamine: an alpha-adrenergic agent for the management of urinary incontinence in the bitch associated with urethral sphincter mechanism incompetence

Ten bitches with urinary incontinence due to incompetence of the urethral sphincter mechanism were treated with phenylpropanolamine hydrochloride at a dose of either 1 mg/kg orally three times daily or 2 mg/kg orally once daily in a prolonged release formulation. The signs of incontinence resolved in all the bitches, and improvements were maintained over periods ranging from one to more than two years, except in one bitch which became refractory to treatment after three months. One bitch which was inadvertently treated at a dose rate of 2.5 mg/kg showed signs of lethargy and inappetence but returned to normal when the dose rate was reduced.     

Importance of urethral length, bladder neck position and vestibulovaginal stenosis in sphincter mechanism incompetence in the incontinent bitch

The urethral length, bladder neck position and presence of vestibulovaginal stenosis were recorded in 42 continent bitches and 57 incontinent bitches diagnosed as having sphincter mechanism incompetence. Incontinent animals had significantly shorter urethras and tended to have intrapelvic rather than intraabdominal bladder necks. There was no statistical difference in the incidence of vestibulovaginal stenosis between continent and incontinent bitches.     

Clinical response and urethral pressure profile changes after phenylpropanolamine in dogs with primary sphincter incompetence

Based on clinical response, urethral pressure profile changes, and lack of side effects, phenylpropanolamine was effective and safe in treating dogs with primary sphincter incompetence. Primary sphincter incompetence was diagnosed in 11 female and 8 male dogs with urinary incontinence. Urodynamics of the dogs were assessed, using a combined urethral pressure profile and urethral sphincter electromyography. Male and female dogs had significantly (P less than 0.05) lower maximal urethral closure pressures, when compared with clinically normally dogs (36.91 +/- 8.20 cm of H2O vs 79.72 +/- 4.61 cm of H2O for female dogs and 48.63 +/- 8.68 cm of H2O vs 99.77 +/- 11.71 cm of H2O for male dogs). After treatment with phenylpropanolamine, there was a significant increase in maximal urethral closure pressure in both sexes to within normal range (77.73 +/- 8.70 cm of H2O in females and 92.50 +/- 14.60 cm of H2O in males). Electromyographic activity was normal before and after treatment. Urinary incontinence resolved clinically in all but 1 male and 1 female dog; however, the condition in these 2 dogs improved considerably. Minimal side effects were seen clinically. Mean arterial blood pressure was not altered by treatment. Plasma estrogen and testosterone concentrations in 8 female dogs were not different from those in continent female dogs. The incontinence in these dogs was considered a sphincter incompetence rather than estrogen responsive.     

Transobturator vaginal tape inside out for treatment of urethral sphincter mechanism incompetence: preliminary results in 7 female dogs

Objectives: To evaluate the clinical efficacy of the transobturator vaginal tape inside‐out (TVT‐O) in incontinent female dogs affected with urethral sphincter mechanism incompetence (USMI) and to determine its urodynamic and morphologic effects. Study Design: Case series. Animals: Incontinent spayed female dogs (n=7). Methods: TVT‐O tape was inserted in 7 incontinent female dogs diagnosed with USMI. Urethral pressure profilometry (UPP) and vaginourethrograms were performed preoperatively, and 1 and 3 months postoperatively. Clinical efficacy of the technique was evaluated and complications reported. Follow‐up information was evaluated by a telephone questionnaire. Results: All dogs were continent immediately after the procedure. Incontinence recurred 2 months after surgery in 1 dog and was treated by phenylpropanolamine administration. At mean follow‐up time of 11.3 months, 6 of 7 dogs were continent. An iatrogenic urethral tear occurred intraoperatively in 1 dog. No postoperative complications were encountered. The postoperative UPPs showed significantly increased maximal urethral closure pressure and integrated pressure. Postoperative vaginourethrograms were unremarkable. The surgical procedure did not modify the location of the urinary bladder neck in dogs with a “pelvic urinary bladder” preoperatively. Conclusions: TVT‐O was efficient in maintaining short term continence in 6 of 7 dogs affected with USMI.     

雄犬尿道插管技术

在兽医临床上,尿道插管术是常用的操作技术之一,用于冲洗膀胱与尿道,根治炎症;导流尿液,规避感染;提供尿道支撑,防止闭塞等。但雄犬因尿道解剖与生理的特殊性,插管比较困难。反复操作必然给犬带来很多痛苦,而且容易损伤尿道黏膜,出现并发症。现有资料对雄犬尿道插管技术的介绍并不多见。笔者在研究雄犬尿道解剖结构与生理特点的基础上,结合临床实践经验,总结了雄犬尿道插管的实际操作技术,并详细分析了插管过程、导尿管留置期间和更换导尿管时应注意的问题及处理方法,以期为临床上科学地应用导尿管及开展泌尿外科动物试验提供一些帮助。