EFFECTS OF BLADDER DISTENTION ON CANINE AND FELINE RETROGRADE URETHROGRAPHY

Retrograde urethrography with viscous contrast medium was performed in male and female dogs and cats before and after bladder distention. The viscosity of commercially prepared contrast medium was increased by addition of an aqueous lubricant. The diameter of the proximal urethra of female dogs (regions 1 and 2) was larger during urethrography (p<0.05) following bladder distention. The diameter of regions 1 and 2 of the proximal uretha of female cats in lateral recumbency was larger during urethrography (p<0.05) following bladder distention. The diameter of the distal urethra of female dogs and cats was not significantly different before or after bladder distention. The diameter of the prostatic urethra of male dogs was larger (p<0.003) following bladder distention. The diameter of the membranous and penile urethra of male dogs was not significantly different before or after urinary bladder distention. Similarly, the diameter of the urethral lumen in male cats was not significantly different before or after bladder distention. The increased viscosity of the contrast medium due to the aqueous lubricant failed to distend all areas of the male and female canine and feline urethra maximally during urethrography when the bladder was not distended. On the basis of the results of this study, the authors recommend urinary bladder distention with a lubricant-free positive contrast medium to generate intravesical hydrostatic pressure sufficient to induce urethral distention. The degree of bladder distention should be determined by digital palpation.     

DIMENSIONS OF THE PROSTATIC AND MEMBRANOUS URETHRA IN NORMAL MALE DOGS DURING MAXIMUM DISTENSION RETROGRADE URETHROCYSTOGRAPHY*

Prostatic and membranous urethral diameter was measured in 24 normal mature male Beagle dogs during maximum distension retrograde urethrocystography. This technique involved retrograde urethral distension by infusion with contrast medium until the urinary bladder was distended and the vesicourethral junction remained opened as observed by fluoroscopy. Lateral and ventro-dorsal radiographs were made during subsequent injections of 5–10 ml of contrast medium. The prostatic urethra was consistently greater in diameter than the membranous urethra. However, the numerical ratio between the prostatic urethral diameter and the membranous urethral diameter varied among these dogs by a factor of 2 at the numerical extremes.     

Colliculus seminalis as a cause of a urethral filling defect in two dogs with Sertoli cell testicular neoplasms

A urethral filling defect in the proximal portion of the pelvic urethra, suggestive of a mass, was detected by positive-contrast retrograde urethrography in 2 dogs with prostatic disease and Sertoli cell neoplasms. Extension of prostatic neoplasia into the urethra or primary urethral neoplasia were considered as explanations for the radiographic finding of an intraluminal filling defect in the pelvic urethra. Masses were visualized and biopsied during prostatic surgery. Masses were nonneoplastic and represented enlargement of the colliculus seminalis.     

Radiologic study of the canine urethra

The structure and function of the canine urethra were studied during retrograde and voiding urethrography in 9 male and 8 female dogs. The lumen of the prostatic portion of the urethra was variable in diameter. During retrograde urethrography, the lumen was narrow with streaks of contrast medium outlining mucosal folds, but during voiding, it was dilated and a spindle-shaped seminal hillock was detected. Retrograde urethrography revealed other regions of the urethra of males and females had a smooth radiographic outline. During voiding urethrography, characteristic identical urethral contractions were observed in the caudal portion of the pelvic urethra (male) and in the caudal half of the urethra (female). Contractions were progressive, occurred where striated muscle was present in the urethral wall, and resulted in an intermittent flow of urine from the urethra. In the male, contractions had a rate of 2.02 +/- 0.23 contraction/s and 1.65 +/- 0.53 in the females. Contractions may have a role in the controlled voiding of small volumes of urine necessary for the repeated marking of territory, in the passage of the ejaculate along the male urethra during copulation, and in the clearance of any residual urine from the urethra at the completion of micturition.     

Use of a self-expanding metallic stent for the treatment of a urethral stricture in a young cat

A 4-month-old intact male domestic shorthair cat was evaluated for urinary outflow obstruction after several weeks of medical management for traumatic urethral rupture. Positive-contrast retrograde urethrography and anterograde cystoscopy performed 4 weeks after the initial urethral injury confirmed a stricture approximately 1cm distal to the bladder trigone at the site of the initial urethral tear. A self-expanding metallic urethral stent (SEMS) was placed under fluoroscopic guidance to relieve the urethral stricture and re-establish luminal patency. After stent placement, the cat was able to void urine normally with minimal urinary incontinence noted. This resolved several months post-stent placement. No known clinical complications persisted other than mild intermittent hematuria.     

ULTRASONOGRAPHIC APPEARANCE OF URETHRAL TRANSITIONAL CELL CARCINOMA IN TEN DOGS

The mucosal margin of the urethra is best assessed by positive contrast urethrography, but ultrasonography offers complementary information such as urethral wall thickness and size of medial iliac lymph nodes. Ultrasonography of the urethra is quick, noninvasive and does not require sedation or general anesthesia. In patients with complete urethral obstruction, ultrasonography may be the only way to image the urethra. Twelve dogs which were presented to Tufts University School of Veterinary Medicine with clinical signs referable to the urinary bladder, urethra or vagina were examined ultrasonographically. Seven were neutered females and five were neutered males. Each dog had a hyperechoic, nonshadowing line at the epithelial surface of the proximal urethra. In the seven female patients and one of the males, the urethral wall was also thick and hypoechoic to surrounding tissue. In the other males, the urethral epithelial changes were at the level of the prostate, and the limits of the urethra were not visible. In six dogs, the urethral change was the only abnormality seen, while in six, bladder wall, bladder luminal and/or prostatic parenchymal changes were also detected. Three patients had hydronephrosis, and one had enlarged medial iliac lyumph nodes. Biopsies were obtained via suction with urinary catheterization (n = 6), exploratory celiotomy (n = 3), urethroscopy (n = 2), or at post-mortem (n = 1). A histopathologic diagnosis of urethral transitional cell carcinoma was obtained in ten dogs. The ultrasonographic appearance was not pathognomonic for transitional cell carcinoma, as one dog with transitional cell dysplasia and one dog with severe ulcerative and necrosupperative cystitis and urethral stricture had similar findings.     

Effects of intravesical hydrostatic pressure and volume on the distensibility of the canine prostatic portion of the urethra

Positive-contrast retrograde urethrocystograms were obtained serially on 12 male dogs weighing 11.4 to 23.2 kg before, during, and after the injection of contrast medium until the urinary bladder neck and prostatic and membranous portions of the urethra remained open and distended as viewed by fluoroscopy. Correlations of intravesical volumes and pressures required to achieve maximum distension of the midprostatic portion of the urethra with body weight and surface area were not significant. Because of the variability in intravesical volumes and pressures encountered at maximum distension of the prostatic portion of the urethra, a dose of contrast material expressed relative to body weight or surface area could not be determined for consistently providing maximum distension of the prostatic portion of the urethra.     

Effects of urinary bladder distention on location of the urinary bladder and urethra of healthy dogs and cats

Evaluation of the anatomic location of the distended and empty urinary bladders and urethras of healthy adult male and female dogs and cats by retrograde urethrocystography revealed substantial variations. In 15 dogs in lateral recumbency with empty bladder lumens, the caudal portion of the urinary bladder was within the pelvic canal in 5 of 7 male and 5 of 8 female dogs. In female dogs examined in ventrodorsal recumbency, only 4 of 8 had the empty urinary bladders in part within the pelvic canal. After luminal distention, 3 of 7 male and 3 of 8 female dogs, while in lateral recumbency, had the urinary bladders in part intrapelvically. However, when female dogs were placed in ventrodorsal recumbency, only 1 of 7 urinary bladders was in part within the pelvis. The urinary bladders of 14 cats were consistently within the abdominal cavity, irrespective of whether the bladder lumen was distended or empty. Urethral flexures occurred in dogs with intrapelvic bladders that were distended or empty. Urethral flexures were not found in cats. The urethras of dogs and cats in lateral recumbency were generally closer to the floor of the pelvis after urinary bladder distention than when the bladder was empty. The urethra of the dogs and cats in ventrodorsal recumbency was to the left or right of or on the midsagittal plane, whether the urinary bladder was empty or distended. A greater degree of lateral displacement was encountered in ventrodorsal recumbency after urinary bladder distention.     

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.     

TRANSITIONAL CELL CARCINOMA OF THE URETHRA IN FOUR FEMALE DOGS: ITS URETHROGRAPHIC APPEARANCE

ansitional cell urethral carcinoma in four female dogs is reported. Lesion distribution in the proximal two thirds of the urethra and the radiographic appearance with retrograde positive contrast urethrography were similar in each dog. The normally smooth longitudinal urethral striations were replaced by multiple small, poorly marginated intraluminal masses that resulted in a generalized moth-eaten appearance. Extension of contrast medium into the periurethral tissues also occurred. Retrograde urethrography, a simple diagnostic technic, aided in establishing a differential diagnosis in dogs that had urine retention and stranguria.     

POSITIVE CONTRAST RETROGRADE URETHROGRAPHY: A USEFUL PROCEDURE FOR EVALUATING URETHRAL DISORDERS IN THE DOG

Positive contrast retrograde urethrography proved to be a useful and relatively simple technic for the evaluation of lower urinary tract disorders in the dog. The case histories of 12 dogs with such disorders were used to illustrate the role of positive contrast retrograde urethrography in the evaluation of urethral and urinary bladder integrity after caudal abdominal and pelvic trauma, and in the investigation of incontinence, stranguria, dysuria, and hematuria.     

Management of traumatic urethral rupture in 11 cats using primary alignment with a urethral catheter

OBJECTIVE: To assess the management of traumatic urethral ruptures using a systematic attempt at urethral catheterisation. METHODS: Eleven cats that had been diagnosed with a traumatic urethral rupture over a five-year period were included in this study. Rupture was assessed by positive-contrast retrograde urethrography. An attempt was made to manage these ruptures by placing an indwelling urethral catheter. RESULTS: The placement of an indwelling urethral catheter, could be performed in 10 out of 11 cats, which indicated a partial rupture. In one cat, catheterisation was not possible because of complete urethral rupture. A urethral catheter was placed into the urinary bladder via the urethra in five animals. In the other five animals, urethral catheterization required cystotomy using a modified 'inside to outside' technique. Urethral catheter removal occurred between five and 14 days after placement. Urethral healing was accomplished in all cases of catheterisation with a good outcome in eight of the 10 cats. Two cats showed clinical signs related to stricture formation during the follow-up period (seven to 72 months). Retrograde urethrography provided a definitive diagnosis of partial rupture in only six of the 10 cases of partial rupture. CLINICAL SIGNIFICANCE: Results suggested that primary alignment with the placement of a urethral catheter should be attempted for the management of traumatic urethral ruptures in cats. Gentle urethral catheterisation seems to be an effective procedure for diagnosing and dealing with partial urethral rupture in cats. Clinical stricture formation can occur, but the risk does not seem to be high. Further studies are warranted in order to define the ideal duration for maintenance of an indwelling urethral catheter in cases of traumatic partial urethral rupture.     

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.     

Urogenital anomalies and urinary incontinence in an English Cocker Spaniel dog with XX sex reversal

A 3‐year‐old dog weighing 8 kg was referred with a disorder of sexual development and persistent urinary incontinence before and after gonadohysterectomy performed at a local animal hospital. Histopathological examination disclosed hypoplasia of the testes, epididymis, pampiniform plexus, and uterus. On ultrasonography, an anomalous structure containing anechoic fluid was identified in the region dorsal to the urinary bladder. An anomalous communication between the proximal urethra and the remnant uterus and vagina was found on retrograde urethrography under fluoroscopy. Reflux of contrast medium into the anomalous structure, suspected to be the uterus and cranial vagina, from the urethra was detected. Computed tomography identified the anomalous structure between the rectum and urethra. The anomalous structure was removed via laparotomy and the urinary incontinence resolved. The diagnosis of XX sex reversal with a developmental anomaly of the genitourinary tract was made on the basis of laparotomy findings and cytogenetic and SRY gene analyses.     

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.     

Prostatic carcinoma in two cats

Clinical, radiological and pathological features of two cats with prostatic carcinoma are reported. In both cats the presenting history included signs of lower urinary tract disease with haematuria and dysuria. Prostatomegaly was visible radiographically in one cat; an irregular intraprostatic urethra was seen on retrograde contrast urethrography in both cats. In one of the cats, neoplasia was suspected on the basis of a transurethral catheter biopsy. Following a poor response to palliative treatment in both cases, euthanasia was performed with histological confirmation of the diagnosis.     

Prostatic carcinoma causing urethral obstruction and obstipation in a cat

A 9-year-old intact male cat was presented for vomiting and straining to defecate. A large abdominal mass was palpated. The urinary bladder was full and non-expressible. Exploratory laparotomy revealed that the mass was compressing the colon and encircling the urethra caudal to the bladder. The mass was removed, the urethra transected, and the urinary bladder marsupialized to the ventral abdominal wall to allow urine drainage. Histopathologic examination of the mass revealed a prostatic carcinoma. The cat died approximately 6 weeks after removal of the mass. This is the first reported case of a prostatic carcinoma causing urethral obstruction and obstipation in a cat.     

Canine prostatic disease--comparison of ultrasonographic appearance with morphologic and microbiologic findings: 30 cases (1981-1985)

A retrospective analysis was made of 30 cases of canine prostatic disease, with the objective of identifying (via a prepubic approach) the 2-dimensional, gray-scale ultrasonographic appearance most often associated with the various spontaneous prostatic diseases. Ultrasonography was of value in characterizing the parenchymal architecture as normal vs focally hyperechoic and diffusely hyperechoic (associated with chronic inflammation and neoplasia) or focally hypoechoic or anechoic (either accompanied by distant enhancement), which was associated with retention cyst or abscess. Further specificity based only on abnormal echotexture was not possible. Ultrasonography facilitated the differentiation of radiographically identifiable prostatomegaly attributable to abscess or neoplasia from apparent prostatomegaly attributable to paraprostatic cyst. An imaging protocol consisting of distention retrograde urethrocystography and prepubic ultrasonography was recommended, as a distended bladder aided ultrasonographic identification of the prostate gland. In addition, the combination of urethral morphologic features and urethroprostatic reflux appearance complemented the ultrasonographic appearance for differentiation of prostatic abscess from prostatic carcinoma. A classification scheme for spontaneous canine prostatic disease combining germane imaging morphologic features with microscopic and microbiologic findings was proposed.     

Anatomical Variations of the Blood Vascular System in Veterinary Medicine. The Internal Iliac Artery of the Dog. Part Two

The aim of this study was to investigate the variability of the internal pudendal artery. Two hundred and thirty‐two pelvic halves from 116 adult dogs were examined. Twenty‐six anatomical variations were found, thirteen occurring in more than 5% of the dogs. Anatomical variations were grouped in relation to the origin of the prostatic/vaginal arteries, middle rectal artery, urethral artery, ventral perineal and caudal rectal arteries. The chi‐squared test was used to analyse differences in sex, side of the body, profile and size, and the results were considered statistically significant when P ≤ 0.05. An identical vascular pattern in both hemipelvises was found for most of the anatomical variations described.     

Urethral transitional cell carcinoma in a cat

A 15-year-old, male neutered cat was referred for investigation of dysuria. A retrograde urethrography was performed which showed two space-occupying masses within the lumen of the mid-to-proximal urethra. Exploratory coeliotomy revealed two urethral masses. Segmental urethrectomy was performed to resect the mass, and the lower urinary tract was reconstructed by vesico-urethral anastomosis. Histopathology showed the mass to be a transitional cell carcinoma with incomplete surgical margins. Tumour regrowth was suspected when dysuria was found approximately 318 days after surgery. Clinical signs were palliated by radiation using weekly fractions of 6 Gy for three weeks. The cat died of unknown causes 386 days postoperatively.