Stone-induced urethral fistula treatment with microfragmented adipose tissue containing mesenchymal stem cells: a case report from veterinary medicine with potential application in humans.

We report on a case of a two-year-old male dog, breed chow-chow, who suffered from urethral fistula as a result of ureterolithiasis. The urethral defect was identified intraoperatively with methylene blue. An autologous regenerative approach was combined with surgical closure of the defect, due to the well-known healing issues of the urethral wall in such conditions. A part of abdominal fat tissue was dissected to produce microfragmented adipose tissue containing mesenchymal stem cells, which was combined with platelet-rich plasma. The final product was applied in the area around the urethral defect closure. One month after the procedure, healing was confirmed with positive-contrast cystography. This therapeutic approach yielded success, and the follow-up period of one year was uneventful. The observed positive outcome of this approach in the canine model may be considered as a starting point for investigating the translational potential of the treatment in human medicine.

Placement of an artificial urethral sphincter in 8 male dogs with urethral diverticulum.

BACKGROUND: Urethral diverticulum (UD) is a poorly defined anomaly consisting of an outpouching of the urethra. Management without surgical resection is not previously reported in dogs. HYPOTHESIS/OBJECTIVES: Report the outcome of male dogs presented for urinary incontinence with UD treated with an artificial urethral sphincter (AUS). ANIMALS: Eight client-owned dogs with UD treated with an AUS. METHODS: Multicenter retrospective study. Medical records from male dogs with urinary incontinence were reviewed. INCLUSION CRITERIA:  diagnosis of a UD by retrograde cystourethrography, cystoscopy, abdominal ultrasonography or contrast computed tomodensitometry (CT) or a combination of these modalities, AUS placement, and at least 1 follow-up. Urinary continence score (UCS) was attributed retrospectively. RESULTS: Median UCS at presentation was 1/5. A contrast cystourethrogram was diagnostic in 8/8 dogs. All diverticula were saccular, and 7/8 were within the prostatic urethra and 1/8 extended up to the membranous urethra. A congenital origin was suspected in 7 dogs and acquired in 1. Concurrent anomalies included renal dysplasia or chronic pyelonephritis (n = 4), bilateral cryptorchidism (n = 3), and pelvic urinary bladder (n = 3). All dogs were poorly/moderately responsive to phenylpropanolamine. Artificial urethral sphincter placement resulted in improvement in continence in all dogs with a median UCS of 4/5 (5/5 in 2/8 dogs, 4/5 in 5/8 dogs, 3/5 in 1/8 dogs). CONCLUSION: Urethral diverticulum should be considered in male dogs with persistent urinary incontinence not responding to medical management. Artificial urethral sphincter placement is an effective therapeutic option that improved continence scores in all dogs.

Occurrence of cardiovascular events in 168 cats with acute urinary tract obstruction.

Background: Cardiovascular dysfunction associated with acute kidney injury has been recently described in veterinary medicine, but limited information is available for cats with urinary tract obstruction (UTO). Objective: This retrospective study aimed to describe the type, frequency, timeline, and risk factors for cardiovascular events (CVEs) in cats treated for acute UTO. Animals and procedures: Medical records of cats admitted to the intensive care unit for either upper (ureteral: UUTO) or lower (urethral: LUTO) UTO from 2016 to 2021 were reviewed. Cardiovascular events were defined as development of arrhythmia, heart murmur or gallop sound, clinical signs consistent with fluid overload (CRFO), or decreased tissue perfusion (DTP). Results: One hundred and sixty-eight cats with UTO were recruited (56 with UUTO and 112 with LUTO). Cardiovascular events were reported in 61.9% of cases, including arrhythmia (33.6%), gallop rhythm (28.1%), heart murmur (15.3%), CRFO (14.4%), and DTP (8.6%). Potassium concentration, preexisting chronic kidney disease, and renal pelvic dilation at abdominal ultrasonography were associated with CVE occurrence in multivariate analysis. Conclusions: This study highlighted frequent CVEs in cats treated for UTO, with a potential strong impact on outcome. Therefore, cardiovascular parameters of cats with preexisting chronic kidney disease or those admitted with hyperkalemia or renal pelvic dilation should be closely monitored.

Survenue d'anomalies cardio-vasculaires chez 168 chats présentés pour obstruction du tractus urinaire. Contexte: Si des anomalies cardiovasculaires secondaires à une insuffisance rénale aigue ont été décrites récemment en médecine vétérinaire, ces données restent limitées concernant les obstructions du tractus urinaire (OTU) chez le chat. Objectif: Décrire le type, la fréquence, le délai d'apparition et les facteurs de risques d'anomalies cardio-vasculaires (ACV) chez des chats hospitalisés pour OTU aigue. Animaux et protocoles: Les dossiers médicaux des chats admis en unité de soins intensifs pour obstruction du tractus urinaire haut ( urétérales-OTUH) et bas (urétrales-OTUB) entre 2016 et 2021 ont été consultés. Les ACV retenus étaient des arythmies cardiaques, le développement de souffles cardiaques et de bruits de galop, les signes relatifs à une surcharge en fluide (SRSF) et de diminution de la perfusion tissulaire (SDPT). Résultats: Cent soixante-huit chats avec des OTU ont été recrutés (56 OTUH, 112 OTUB). Des ACV ont été observés dans 61,9 % des cas, incluant des arythmies (33,6 %), l'apparition de bruits de galop (28,1 %) et de souffles cardiaques (15,3 %), des SRSF (14,4 %) et des SDPT (8,6 %). La concentration plasmatique en potassium, la présence d'une MRC sous-jacente et d'une dilatation pyélique à l'échographie abdominale ont été associées à la présence d'ACV par l'analyse multivariée. Conclusions: Cette étude montre que les ACV surviennent fréquemment chez les chats présentés pour OTU, et suggère un impact sur la survie de ces animaux. Les animaux avec un historique de MRC, ceux présentés avec une hyperkaliémie et/ou avec une dilatation pyélique à l'échographie abdominale devraient être surveillés avec plus de précautions que les autres.(Traduit per les auteurs).

Urethrorectal fistula ligation and transection in a dog with a history of unilateral abdominal cryptorchidism and misdiagnosed anal gland disease.

A 10-month-old unilaterally cryptorchid male labradoodle dog was presented to a specialty surgery referral center with a reported history of persistent anal sac leakage that was unresponsive to conservative management. The dog underwent castration and left anal sacculectomy but was witnessed urinating from the anus postoperatively. A contrast urethrogram was performed, and a urethrorectal fistula located between the distal portion of the pelvic urethra and the caudal aspect of the rectum was diagnosed. One week later, the dog underwent ligation and transection of the fistula. Surgery was successful and the dog recovered unremarkably with complete resolution of clinical signs. A contrast urethrogram 1 mo after surgery confirmed the successful ligation and transection of the fistula. Key clinical message: To the authors' knowledge, this is the first clinical report of urethrorectal fistula ligation and transection in a dog with unilateral abdominal cryptorchidism and misdiagnosed anal sac disease. Our findings underscore the importance of a thorough physical examination, history taking, and clinical workup for appropriate diagnosis and treatment of multiple congenital abnormalities.

Ligature et transection de la fistule urétrorectale chez un chien ayant des antécédents de cryptorchidie abdominale unilatérale et de maladie des glandes anales mal diagnostiquée. Un chien Labradoodle mâle unilatéralement cryptorchide âgé de 10 mois a été présenté à un centre de référence en chirurgie spécialisée avec des antécédents signalés de fuite persistante du sac anal qui ne répondait pas à une prise en charge conservatrice. Le chien a subi une castration et une sacculectomie anale gauche, mais a été vu en train d'uriner par l'anus après l'opération. Un urétrogramme de contraste a été réalisé et une fistule urétrorectale située entre la partie distale de l'urètre pelvien et la face caudale du rectum a été diagnostiquée. Une semaine plus tard, le chien a subi une ligature et une section de la fistule. La chirurgie a été un succès et le chien s'est rétabli sans particularité avec une résolution complète des signes cliniques. Un urétrogramme de contraste 1 mois après la chirurgie a confirmé la réussite de la ligature et de la section de la fistule.Message clinique clé :À la connaissance des auteurs, il s'agit du premier rapport clinique de ligature et de transection de fistule urétrorectale chez un chien atteint de cryptorchidie abdominale unilatérale et d'une maladie du sac anal mal diagnostiquée. Nos résultats soulignent l'importance d'un examen physique approfondi, d'une anamnèse et d'un bilan clinique pour un diagnostic et un traitement appropriés des anomalies congénitales multiples.(Traduit par Dr Serge Messier).

Risk factors of enterococcal bacteriuria in cats: A retrospective study.

Objective: To determine if factors associated with urothelial damage and inflammation, including urinary catheterization, urinary obstruction, and urolithiasis are associated with the presence of enterococcal bacteriuria in cats. Animals: Thirty-one cats with Enterococcus spp. bacteriuria and 31 cats with Escherichia coli bacteriuria. Procedure: A retrospective case-control study with cases and controls identified by records search for Enterococcus spp. (case) and E. coli (control) bacteriuria from August 1, 2014 to July 31, 2019. Cases and controls were balanced with respect to average age. Binary logistic regression was used to estimate and test whether the odds of having Enterococcus spp. bacteriuria (instead of E. coli) were associated with the presence of any characteristic. Results: Urinary catheterization, urinary obstruction, and urolithiasis were not observed more often in Enterococcus cases versus E. coli controls (19% versus 25%, P = 0.543; 19% versus 32%, P = 0.244; and 16% versus 16%, P = 1, respectively). Signs of lower urinary tract disease were significantly less common in Enterococcus cases than in E. coli controls (OR: 0.30; 95% CI: 0.10 to 0.83, P = 0.02). Hematuria was significantly less common in cases than controls (P = 0.048). Conclusion: No association was identified between urinary catheterization, urolithiasis, or any other comorbidities (hyperthyroidism, chronic kidney disease) and enterococcal bacteriuria in cats. Clinical relevance: Unlike in humans and dogs, urothelial damage and inflammation caused by factors such as urinary catheterization and urolithiasis may not be the mechanism for enterococcal bacteriuria in cats.

Facteurs de risque de bactériurie à entérocoque chez le chat : une étude rétrospective. Objectif: Déterminer si les facteurs associés aux lésions et à l'inflammation urothéliales, y compris le cathétérisme urinaire, l'obstruction urinaire et les lithiases urinaires, sont associés à la présence de bactériurie à entérocoque chez le chat. Animaux: Trente et un chats avec bactériurie à Enterococcus spp. et 31 chats atteints de bactériurie à Escherichia coli. Procédure: Une étude cas-témoins rétrospective avec des cas et des témoins identifiés par la recherche de dossiers pour bactériurie à Enterococcus spp. (cas) et à E. coli (témoin) du 1er août 2014 au 31 juillet 2019. Les cas et les témoins étaient équilibrés par rapport à l'âge moyen. La régression logistique binaire a été utilisée pour estimer et tester si la probabilité d'avoir une bactériurie à Enterococcus spp. (au lieu d'E. coli) était associée à la présence de n'importe quelle caractéristique. Résultats: Le cathétérisme urinaire, l'obstruction urinaire et la lithiase urinaire n'ont pas été observés plus souvent chez les cas avec Enterococcus spp. par rapport aux témoins avec E. coli (19 % vs 25 %, P = 0,543; 19 % vs 32 %, P = 0,244; et 16 % vs 16 %, P = 1, respectivement). Les signes de maladie des voies urinaires inférieures étaient significativement moins fréquents chez les cas à Enterococcus que chez les témoins à E. coli (OR : 0,30; IC à 95 % : 0,10 à 0,83, P = 0,02). L'hématurie était significativement moins fréquente chez les cas que chez les témoins (P = 0,048). Conclusion: Aucune association n'a été identifiée entre le cathétérisme urinaire, la lithiase urinaire ou toute autre comorbidité (hyperthyroïdie, maladie rénale chronique) et la bactériurie à entérocoque chez le chat. Pertinence clinique: Contrairement aux humains et aux chiens, les lésions urothéliales et l'inflammation causées par des facteurs tels que le cathétérisme urinaire et la lithiase urinaire peuvent ne pas être le mécanisme pour la bactériurie à entérocoque chez les chats.(Traduit par Dr Serge Messier).

Traumatic Rectovesicular Fistula in a Dog.

A 7 mo old intact male Australian cattle dog presented for evaluation of a suspected urethrorectal fistula after being examined by the primary veterinarian for leaking of urine from the rectum at rest and when posturing to urinate. Advanced imaging identified a caudally retroflexed urinary bladder, several healing pelvic fractures, and a rectovesicular fistula. Primary surgical repair of the fistula was performed. The dog recovered well from surgery and was urinating and defecating normally as of 5 mo after the operation. This is the first report of a traumatic rectovesicular fistula in the veterinary literature.

Application of buccal mucosal graft to establish a new urination passage in male cats with penile traumatic injury.

Two male cats were presented with penile part of urethra injury due to dog attacks to the perineum and genitalia area. Chronic wound around a remained penile part of urethra due to the dog bite and perineal area was evident due to urine irritation. The buccal mucosa was harvested and subsequently placed on the granulation tissue of the wound to reconstruct the urinary passage. The buccal mucosal graft completely attached to the skin and urethra without any complications. From the follow-up at 3 months, the cats were able to urinate normally and the skin irritation from urine was resolved. In summary, the buccal mucosa is a good graft source and is suitable for the reconstruction of the urinary passage in severe and complicated cases of penile part of urethra injury in male cats.

Surgical treatment and outcome of sterile prostatic cysts in dogs.

OBJECTIVE: To describe the surgical treatment and outcome of a large cohort of dogs with sterile prostatic cysts (PCs). STUDY DESIGN: Retrospective study. ANIMALS: Forty-four client-owned dogs. METHODS: Dogs with sterile PCs with at least 6 months of follow-up were included. Clinical variables, type of surgery, complications, recurrences, and outcomes (telephonic interviews or rechecks) were recorded. RESULTS: Extra- and intraparenchymal cysts were diagnosed in 29 and 11 dogs, respectively. Four dogs had both types. Extraparenchymal cysts were treated by partial resection and omentalization (n = 22) and complete resection (n = 7). Drainage and intracapsular omentalization were performed in all dogs with intraparenchymal cysts. The four dogs with both types of cyst were treated by omentalization. Resolution was documented in 39/44 dogs (88.6%). Intraoperative complications occurred in one dog (urethral tear). Major complications resulting in death occurred in three dogs (oliguric kidney injury, cardiac arrhythmia, and persisting urinary tract obstruction). Minor complications (n = 10) consisted of temporary urinary incontinence (n = 2), permanent urinary incontinence (n = 5), urinary retention (n = 2), and dysuria (n = 1). Recurrence occurred in two dogs with extraparenchymal cysts. Median long-term follow-up was 528 days (range, 250-730 days). Thirty-nine dogs had no signs associated with prostatic disease at long-term follow-up. CONCLUSION: Partial or complete resection and/or omentalization of sterile PCs led to resolution of clinical signs in most dogs, although postoperative urinary incontinence was frequent. IMPACT: This study is the largest case series relative to canine sterile PCs treated surgically and provides evidence on the prognosis and rate of complications.

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.

[Management of urethral stones in dogs using pneumatic and laser lithotripsy]. / Management von Urethralsteinen beim Hund mittels pneumatischer und laserenergetischer Lithotripsie.

OBJECTIVE: Description of clinical experience with two different lithotripsy modalities for treatment of urethral stones in dogs. MATERIAL AND METHODS: Retrospective analysis (October 2016 - November 2017) of medical records from dogs with urinary stones that underwent transurethral pneumatic or laser lithotripsy. RESULTS: In 28 male and 5 female dogs, either pneumatic lithotripsy (39 %) or laser lithotripsy (61 %) was performed. In the urethra, stone free rates of 100 % in females and over 85 % in males could be achieved using either fragmentation modality. In 3 of 28 (11 %) male dogs, after fragmentation of urethral stones, urethral patency was impaired because of endoscopically suspected polypoid urethritis requiring urethrostomy. In 8 out of 28 (29 %) male dogs and in 1 of 5 (20 %) female dogs, an additional lithocystotomy was necessary to achieve stone-free status in the lower urinary tract. CONCLUSION AND CLINICAL RELEVANCE: Transurethral pneumatic or laser lithotripsy of urinary stones is a successful procedure in dogs. Major pathological conditions of the urethral mucosa may require further surgical or interventional methods for the restoration of a functional urethra.

An application of sublingual mucosa to establish a new urination passage in male cats with complications after urethrostomy.

This is the first study of using sublingual mucosae to establish a new urination passage in male cats suffering from complications from prior urethrostomy. In total, five domestic male cats afflicted with various complications, such as urethra stricture, scalding dermatitis, and urinary tract infection, after urethrostomy were included in the study. Sublingual mucosa was harvested to graft with abdominal muscles and further made into a tube connecting with the remaining urethra of the bladder at the cranial end and with the prepuce at the caudal end, serving as a new passage for urination. Postoperatively, all cats were alive and well recovered with no complications both in the oral cavity and at the surgical site. Radiography with contrast medium at two weeks and six months after surgery showed no leakage, stricture, or abnormality of the new urination passage. Moreover, all cats were able to urinate from the prepuce without any difficulties or signs of discomfort.

Long-term outcome of the transobturator vaginal tape inside out for the treatment of urethral sphincter mechanism incompetence in female dogs.

OBJECTIVE: To evaluate the long-term efficacy of the transobturator vaginal tape inside out (TVT-O) in female dogs with urethral sphincter mechanism incompetence (USMI). STUDY DESIGN: Retrospective study. ANIMALS: Incontinent spayed female dogs (n = 12). METHODS: TVT-O tape was inserted in 12 incontinent bitches diagnosed with USMI. Follow-up information was evaluated by a telephone questionnaire, and a continence score was attributed. RESULTS: One year after surgery, 7 of 12 (58%) dogs were completely continent. Two dogs were removed from the long-term analysis (1 dead and 1 lost). At a median follow-up time of 85 months (range, 28-95), 4 of 10 dogs were completely continent without medical treatment. Incontinence recurred in 6 dogs at a median time of 2 months after surgery (range 1-20). Among these 6 dogs, 4 regained continence, and 2 had sporadic episodes of incontinence with additional medical treatment. No postoperative complications were encountered. CONCLUSION: TVT-O alone was successful in maintaining long-term continence in 40% of the dogs. Additional postoperative medical treatment was effective in restoring continence in another 40% of the dogs. CLINICAL SIGNIFICANCE: TVT-O provides an alternative treatment of USMI in female dogs that is safe and less invasive than standard surgical techniques.

Reconstruction of urethral defects using a fascia lata autograft in a dog.

A castrated male Shih-Tzu dog was presented for evaluation of urine leakage after urethrotomy. A fistula with urine leakage was identified in the perineal region. On retrograde urethrography, the contrast extravasated from the penile urethra into the subcutaneous tissue of the perineum. Urine leakage with urethrocutaneous fistula was diagnosed. During surgery, the disrupted urethra wall and two urethral defects were identified. A fascia lata autograft was used, rather than primary repair of the urethra. Two pieces of fascia lata were harvested and sutured to the urethral defects. The fistula was treated with debridement and drainage. No evidence of urine leakage and dysuria was noted 6 months postoperatively. Thus, this case report describes successful urethral reconstruction using a fascia lata autograft.

Long-Term Outcome of Female Dogs Treated with Static Hydraulic Urethral Sphincter for Urethral Sphincter Mechanism Incompetence.

The purpose of the study was to report the postoperative outcome, complications, and long-term follow-up of the use of a static hydraulic urethral sphincter for the management of urethral sphincter mechanism incompetence in female dogs. Medical records were reviewed to extract information on long-term (>365 days) outcome data. Telephone owner questionnaire was performed to assess postoperative urinary continence scores (scale 1-10, where 10 is complete continence) and the presence and frequency of complications. Twenty female dogs were included. Mean (±standard deviation) time to follow-up was 1,205.1 (±627.4) days. Median continence score/10 (range) was 3.5 (2-6) preoperatively, and 9.0 (7-10) at the last follow-up. Median continence score was significantly higher at all time points postoperatively compared with before surgery (P < .001). Complete continence was achieved in 90% of bitches. Minor complications occurred in 13 bitches and included dysuria (8), bacterial cystitis (8), longer urination time (10), incisional seroma (5), urinary retention (3), hematuria (2), and pain when urinating (2). Major complications occurred in one dog (static hydraulic urethral sphincter removed 28 mo after placement). Continence scores were sustainably improved in the long-term. Complications were mostly minor. Urinary tract infections were the most common but resolved with conventional antibiotic treatment.

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.

Suspected congenital urethral diverticulum in a dog.

A 2-year-old neutered male dog with a history of urinary incontinence, recurrent urinary tract infections, and unilateral cryptorchidism was presented with an acute onset of perineal swelling. Urinary contrast studies revealed a urothelial lined structure in the perineum. Surgical resection of 80% to 90% of this structure, suspected to be a congenital urethral diverticulum, was successful.

Diverticule urétral congénital soupçonné chez un chien. Un chien mâle stérilisé âgé de 2 ans ayant une anamnèse d'incontinence urinaire, d'infections des voies urinaires récurrentes et de cryptorchidie unilatérale a été présenté suite à l'apparition aiguë d'enflure périnéale. Des épreuves de contraste urinaire ont révélé une structure urothéliale recouverte dans le périnée. Une résection chirurgicale de 80 % à 90 % de cette structure, soupçonnée d'être un diverticule urétral congénital, a été réalisée avec succès.(Traduit par Isabelle Vallières).

Urethral prolapse corrected by microsurgery in a cat: a case report.

Urethral prolapse is a rare condition in dogs and cats. A 7-month-old male cat presented with intermittent penile bleeding and a red mass protruding from the tip of the penis. Urethral prolapse was diagnosed by using a surgical microcamera to examine the genital area. Urethroplasty and preputial advancement surgery were performed using a surgical microscope, to successfully correct the urethral prolapse.

Urethral diverticulum and urolithiasis in a female guinea pig (Cavia porcellus).

CASE DESCRIPTION A 5-year-old sexually intact female guinea pig was evaluated because of mild dysuria and a subcutaneous mass located cranioventral to the urogenital openings. CLINICAL FINDINGS Non-contrast-enhanced CT and surgical exploration of the distal aspect of the urethra revealed a urethral diverticulum with an intraluminal urolith. Analysis revealed that the urolith was composed of calcium carbonate and struvite. TREATMENT AND OUTCOME The urolith was surgically removed and ablation of the urethral diverticulum was attempted. Approximately 3 months later, the guinea pig was reevaluated for masses in the perineal region, and positive-contrast urethrocystography revealed 2 uroliths present in the same diverticulum. Uroliths were manually expressed with the patient under general anesthesia. Approximately 2 weeks later, urethroplasty was performed to create an enlarged stoma with the diverticulum, thereby preventing urine from pooling in the diverticulum and potentially reducing the risk of future urolith formation. The urethroplasty site healed well with no reported complications or evidence of urolith recurrence 6 months after surgery. CLINICAL RELEVANCE Urolithiasis is common in guinea pigs, and urethral diverticulum and intraluminal urolith formation should be considered as a potential differential diagnosis for a subcutaneous mass along the distal aspect of the urethra. Creation of a urethral stoma from a urethral diverticulum via urethroplasty achieved a successful outcome in this patient.

Urethral Sphincter Mechanism Incompetence in 163 Neutered Female Dogs: Diagnosis, Treatment, and Relationship of Weight and Age at Neuter to Development of Disease.

BACKGROUND: Urethral sphincter mechanism incompetence (USMI) is the most common cause of urinary incontinence in neutered bitches and is most common in dogs weighing >20 kg. OBJECTIVES: To describe a population of neutered bitches with USMI and investigate their initial presentation, the relationship between weight and age at neuter, and treatment. ANIMALS: One hundred and sixty-three female dogs with USMI (UI) diagnosed between January 2009 and December 2012, and 193 continent neutered control (C) bitches. METHODS: Retrospective data were collected from neutered female dogs with USMI and healthy, continent neutered females presented between January 2009 and December 2012. RESULTS: Urinary incontinent dogs weighed more than C dogs (P = .003), and there was no difference in age at neuter. The relationship between weight at diagnosis and age at neuter was found to impact the hazard of USMI. A decrease in the hazard of USMI was found in dogs weighing >25 kg for every month delay of neuter in the first year. The hazard did not change for dogs <15 kg. Median time from neuter to development of incontinence was 3.73 years. Phenylpropanolamine was prescribed in 75.5%, diethylstilbestrol in 21.5%, and both in 3.1% of dogs. CONCLUSIONS AND CLINICAL IMPORTANCE: Neutering bitches expected to be >25 kg adult weight later in their first year may decrease the hazard of developing USMI, whereas age at neutering of bitches <25 kg may not impact continence. Heavier dogs have increased risk of USMI, and onset occurs within a few years of neuter.