Abstract
Objectives
The objective of this retrospective study was to describe the feline population presented for urinary incontinence at a veterinary teaching hospital between 2009 and 2019, with a particular focus on cats with a non-neurologic underlying cause.
Methods
The medical records of cats diagnosed with urinary incontinence were retrospectively evaluated. Signalment, clinical presentation, results of diagnostic tests, diagnosis of the underlying cause and treatments were recorded. When information was available, outcome was recorded and follow-ups divided into three time frames (0–1 week, 1 week to 3 months and >3 months).
Results
Thirty-five cats were presented with urinary incontinence. Of these, 18 cats with complete medical records presented urinary incontinence of non-neurologic origin. The most common clinical signs at presentation were urine leakage while resting (12/18), urine-soiled perineum (8/18), urine dribbling (8/18) and no spontaneous micturition (5/18). The most common underlying cause was urethral obstruction (67%; 12/18), with a majority due to urethral strictures (58%; 7/12). Other causes were suspected inflammation (2/12), neoplasia (1/12), urolithiasis (1/12) and foreign body (1/12). In 8/10 cats in which it was performed, cystoscopy and contrast cystourethrography were the methods that led to the diagnosis. Twelve cats with urethral obstruction underwent interventional procedures, resulting in complete resolution of incontinence in 7/12 and improvement in 1/12. Urinary tract infection was a common complication after 3 months (4/18).
Conclusions and relevance
When incontinence of non-neurologic origin is suspected in a cat, urethral obstruction should be considered. Advanced imaging studies (cystoscopy and contrast studies) are useful for diagnosis. A good prognosis was reported in cats undergoing interventional procedures with no long-term treatment.
Keywords: Urinary incontinence, urethral obstruction, urethral stricture, FLUTD
Introduction
Urinary incontinence (UI) is defined as an involuntary loss of urine through the urethra. 1 The usual clinical signs include intermittent or continuous urine dribbling accompanied or not by normal voiding and/or nocturia. 2 Sometimes only persistent soiling of the perineum is noted. In cats, differentiating UI from inappropriate voluntary urination and pollakiuria can be challenging. 3 Although UI is the second most common urinary tract disorder in dogs, 4 it is relatively uncommon in cats, representing 4% of lower urinary tract disorders in a large epidemiologic study. 5
Different classifications of UI exist according to the anatomic region affected (ie, bladder, urethra, etc), to the phase of micturition (storage or voiding disorder) or whether the origin is neurologic (lesions affecting the nervous system that control the lower urinary tract) or not. 1
Little information is available in cats regarding the causes, diagnostic features and management of UI. Available studies are case reports or retrospective analyses with a small number of patients. Some authors suggest that neurologic lesions are the most common etiology, in contrast to what is reported in dogs. 6 A recent retrospective study described a predominance of congenital and acquired conditions most commonly involving the spinal cord. 7 In this analysis, the prevalence of cats with UI was 0.2%, with approximately half (24/45) presenting voiding disorders, with 15/24 diagnosed with spinal cord disease and the other half (21/45) of the cases were diagnosed with storage disorders (3/21 diagnosed with spinal cord disease). Urethral sphincter mechanism incompetence (USMI) has also been associated with various causes, including spaying,8–10 feline leukemia virus 10 or anatomic abnormalities such as urethral hypoplasia.11–15 Other causes of UI included ectopic ureter,13,16–18 non-urolith urethral obstructions such as urethral stricture19–22 and, frequently, congenital23–26 and acquired abnormalities.27–30
Our first objective was to compare the signalment of cats presented for neurologic vs non-neurologic causes of incontinence to a teaching hospital over the same time. The second and main objective of this retrospective study was to describe clinical presentation, diagnostic tests, management and outcome of cats exclusively with non-neurologic UI.
Materials and methods
Case selection and data collection
Using keywords, a computerized medical records search of cats was performed from January 2009 to December 2019 at the Veterinary Teaching Hospital of the University of Montreal (CHUV). The keywords were either synonyms to describe UI, its management or common expressions that could have been used by owners (UI, urinary loss, urinary leak, urinary dysfunction, inappropriate urination, dribbling, urinary soiling, urethral stricture, urethral stenosis, urethral stent, recurrent urinary tract infection [UTI]). Cases were included only if the diagnosis of UI appeared in the medical file. Data collected included signalment, presenting complaint, physical examination, neurologic examination performed by a board-certified neurologist and previous medical history (in regard to the urogenital tract). Neurologic examination was recorded if available. Age was approximated to the closest half year at the time of presentation. Complete blood count, serum biochemistry, urinalysis, urine culture and diagnostic imaging results (radiographs, ultrasound, contrast cystourethrography) were collected. Cats undergoing cystoscopy by a board-certified internist had the cystoscopic examination recorded. Response to medical and interventional therapies along with outcomes were included if available in the medical file. Outcome was expressed as whether or not the cat was continent, or if there was an improvement of the incontinence according to the owner. Follow-ups were divided into three categories depending on the time frame: 0–1 week; 1 week to 3 months; and >3 months. Medical, surgical and interventional therapies were reviewed, and the responses to therapy were also recorded. Cats were excluded if the diagnosis of UI was unclear or if it could have been attributed to pollakiuria or inappropriate urination. After recording this information, cats were divided into two groups: neurologic or non-neurologic, based on the history, physical examination, neurologic examination and diagnostic imaging. The non-neurologic group was then divided depending on the site of the anatomic lesion causing UI (urethra, bladder, other).
Signalment and final diagnosis were reported for the neurologic group. A descriptive analysis that included signalment, clinical presentation, laboratory and imaging findings, treatment and outcome was undertaken for the non-neurologic group, the focus of this study. In order to look for differences in signalment between both groups, a χ2 test was used to compare the prevalence of sex and breed (categorized as purebred or mixed breed for the statistical analysis) between the two groups. Ages were transformed using log-base 10 to normalize distribution. Mean age was compared between groups by unequal variance t-test. P values <0.05 were considered to be significant.
Results
Over the study period (January 2009–December 2019), a total of 40 cats were diagnosed with UI at the CHUV, representing 0.25% (40/15,963) of the hospital feline case load. The underlying cause of UI could not be established in five patients owing to owner reluctance to perform further investigations (3/40) or incomplete medical records (2/40). These patients were excluded from the study. Ultimately, a total of 35 cats were included in the analysis.
Definitive diagnoses
The cause of UI was determined to be non-neurologic in 18/35 (51%) patients and neurologic in 17/35 (49%) patients (Table 1).
Table 1.
Etiologies of urinary incontinence depending on underlying etiology and anatomic location
| Cause | Non-neurologic (n = 18) | Neurologic (n = 17) | ||
|---|---|---|---|---|
| Anatomic location | Urethral (n = 12) | Bladder (n = 5) | Other (n = 1) | Spinal cord |
| Urethral stricture (7): Perineal urethrostomy site (3) Unknown origin (4) Neoplasia (1) Foreign body (1) Uroliths (1) Inflammation (2): Feline idiopathic cystitis with urethral spasm (1) Penile urethral necrosis of unknown origin with urethritis (1) |
Detrusor atony (2) Urinary tract infection (3) |
Hepatic encephalopathy secondary to portosystemic shunt (1) | Tail avulsion (4) Congenital (4): Stenosis of the vertebral canal (1) Spina bifida with meningocele (1) Myelodysplasia with thoracolumbar syringomyelia (1) Tethered spinal cord syndrome (1) Neoplasia (high-grade spinal lymphoma [1]) Herniated disk (1) Degenerative myelopathy (2) Infectious: feline infectious peritonitis (1) Suspicion of a myelopathy either associated with a trauma and vertebral fractures (3) or a suspected misalignment of lumbosacral vertebrae (1) |
|
Of the 17 cats in the neurologic group, diagnoses were tail avulsion (4/17 [23%]), congenital (stenosis of the vertebral canal: 1/17 [6%]; spina bifida with meningocele: 1/17 [6%]; myelodysplasia with thoracolumbar syringomyelia: 1/17 [6%]; tethered spinal cord syndrome: 1/17 [6%]), neoplasia (high-grade spinal lymphoma: 1/17 [6%]), herniated disk (1/17 [6%]), degenerative myelopathy (2/17, [12%]), infectious (feline infectious peritonitis: 1/17 [6%]), or suspicion of a myelopathy either associated with a trauma and vertebral fractures (3/17 [18%]) or of a suspected misalignment of lumbosacral vertebrae (1/17 [6%]).
For 12/18 cats (67%) in the non-neurologic group, UI was caused by urethral outlet obstruction. Urethral stricture was diagnosed in 7/18 (39%) patients (three at a perineal urethrostomy site and four of unknown origin). Other causes of urethral outlet obstruction were inflammation in two patients (11%; suspected idiopathic cystitis in 1/2 patients with urethral spasm and penile urethral necrosis of unknown origin with urethritis possibly due to multiple catheterizations in 1/2 cats), obstructive urethral carcinoma in one patient, urethral stones in one patient and foreign body (hair agglomerate) in one patient. Of the 12 cats with a urethral lesion, five cats (5/12 [42%]) were also suspected to have concurrent secondary detrusor atony based on bladder palpation (flaccidity and large size of the bladder) and diagnostic imaging (severe overdistension of the bladder either on abdominal radiographs or abdominal ultrasound). For 5/18 (27%) cats, the lesion causing UI was located to the bladder. More particularly, detrusor atony was suspected in 2/18 cats (11%); however, the underlying cause could not be determined but was suspected to be secondary to previous episodes of urethral obstruction based on history and because medical imaging did not reveal a current urethral obstruction. Three cats (3/18 [17%]) were diagnosed with a UTI: one cat (1/3) was diagnosed with an encrusted cystitis secondary to Proteus mirabilis and was suspected of having concurrent detrusor atony. Finally, one cat (1/18 [6%]) could not be classified into any anatomic category as its UI was secondary to hepatic encephalopathy caused by a portosystemic shunt (classified in ‘other’).
Signalment
Among the neurologic group, 13/17 (76%) cats were male, and 4/17 (24%) cats were female. All were neutered. Breeds were as follows: 14/17 domestic shorthair (82%), 1/17 Manx (6%), 1/17 Bobtail crossed with Siamese (6%) and 1/17 Ragdoll (6%). Median age was 5 years (range 0.5–17) (Table 2).
Table 2.
Comparison of signalment between the non-neurologic and neurologic groups
| Group signalment |
Non-neurologic (n = 18) | Neurologic (n = 17) |
|---|---|---|
| Sex | 12/18 (67%) male 6/18 (33%) female |
13/17 (76%) male 4/17 (24%) female |
| Breed | 15/18 (83%) domestic shorthair 2/18 (11%) Manx 1/18 (6%) Highland Lynx |
14/17 (82%) domestic shorthair 1/17 (6%) Manx 1/17 (6%) Bobtail crossed with Siamese 1/17 (6%) Ragdoll |
| Age | Median 12 years (range 0.5–20) | Median 5 years (range 0.5–17) |
In the 18 cats with a non-neurologic cause included in this study, 12/18 (67%) were male (all neutered but one) and 6/18 (33%) were female (all neutered). Breeds were as follows: 15/18 (83%) domestic shorthair or domestic longhair, and 3/18 (17%) pure breeds (Manx [2/18] and Highland Lynx [1/18]). Median age was 12 years (range 0.5–20) (Table 2).
There was no significant difference in breed (P = 1.0), sex (P = 0.44) or body weight between groups (neurologic vs non-neurologic) (P = 0.52).
For the remainder of the study, we focused exclusively on the non-neurologic group.
Clinical signs
In the 18 cats with a non-neurologic cause, UI was the most common presenting complaint (10/18 [56%], 6/10 with urethral lesion). However, in addition to UI, cats were presented to the hospital for other reasons, including investigation of lower urinary tract signs (dysuria for 4/18 cats [22%]: 3/4 with urethral lesion), recurrent UTI (3/18 [17%], all with urethral lesion) and recurrent urinary obstruction after a perineal ureterostomy (PU; 1/18 [6%] with urethral lesion).
The most common recorded clinical signs are detailed in Table 3 and were classified according to the location of the anatomic lesion. Cats could present one or more clinical signs. Urine leakage while resting or laying down was the most common presenting sign for 12/18 patients (67%). Cats presented at least one lower urinary tract sign other than UI (pollakiuria, dysuria, hematuria, stranguria, periuria) for 10/12 (83%) cats with a urethral lesion and 3/5 (60%) cats with a bladder lesion. The median onset of UI prior to presentation was 30 days (range 1 day to 1.5 years), and – more particularly – 30 days in cats with a urethral lesion (range 1 day to 1 year), 330 days (range 3 days to 1.5 years) in cats with a bladder lesion and 14 days for the cat presenting hepatic encephalopathy.
Table 3.
Presenting clinical signs in cats with urinary incontinence related to a non-neurologic cause
| Presenting clinical sign (n =18) | Total cats affected (n = 18) | Urethral lesion (n = 12) | Bladder lesion (n = 5) | Other (n = 1) |
|---|---|---|---|---|
| Urine leakage while resting/laying down | 12 | 8 | 3 | 1 |
| Urine-soiled perineum | 8 | 7 | 1 | 0 |
| Urine dribbling when walking | 8 | 7 | 1 | 0 |
| Pollakiuria | 7 | 6 | 1 | 0 |
| Dysuria | 6 | 5 | 1 | 0 |
| No spontaneous micturition | 5 | 3 | 2 | 0 |
| Hematuria | 3 | 1 | 2 | 0 |
| Stranguria | 5 | 4 | 1 | 0 |
| Periuria | 2 | 1 | 1 | 0 |
Five cats (5/18 [28%]) had previously undergone perineal urethrostomy surgery.
Physical examination findings are summarized in Table 4. In cats with UI secondary to a disorder of the urethra (12/18), the bladder was large and firm and difficult to express in 5/12 cats (42%), firm and difficult to express in 1/12 cats (8%), distended and flaccid in 2/12 cats (17%; 1/2 easy to express and 1/2 hard to express) and normal in 2/12 cats (17%). A tubular mass was present in the caudal abdomen in 1/12 cats. Three cats with a urethral lesion had vaginitis or balanoposthitis, including severe vaginitis diagnosed in the cat with a foreign body. In cats with UI due to a bladder infection (5/18), bladders were small and firm in 2/5 patients (40%), and large, flaccid and easily expressed in 1/5 patients (20%). The bladder appeared normal on palpation in the one cat with hepatic encephalopathy. No information regarding the bladder size and/or the ability to manually express the bladder was recorded in the medical files of 6/18 (33%) cats.
Table 4.
Physical examination findings on presentation in cats with urinary incontinence related to a non-neurologic cause
| Physical examination | Number of cats affected (n = 18) | Urethral lesion (n = 12) | Bladder lesion (n = 5) | Other (n = 1) |
|---|---|---|---|---|
| Large and firm bladder | 5 | 5 | 0 | 0 |
| Easily expressed | 0 | 0 | 0 | |
| Difficult to express | 5 | 0 | 0 | |
| Firm bladder (size unknown) and difficult to express | 1 | 1 | ||
| Urine-soiled perineum | 8 | 6 | 2 | 0 |
| With urine-scalding dermatitis | 3 | 3 | 0 | 0 |
| Large and flaccid bladder | 3 | 2 | 1 | 0 |
| Easily expressed | 1 | 1 | 0 | |
| Difficult to express | 1 | 0 | 0 | |
| Normal bladder | 3 | 2 | 1 | |
| Balanoposthitis/vaginitis | 3 | 3 | ||
| Small and firm bladder | 2 | 0 | 2 | 0 |
| Easily expressed | 0 | 1 | 0 | |
| Difficult to express | 0 | 1 | 0 | |
| Perineal urethral mass | 1 | 1 | 0 | 0 |
| Easily expressed | 1 | 0 | 0 | |
| Neurologic examination | 9 | 6 | 2 | 1 |
| Normal with type of bladder | 2 with large, flaccid bladder; 1 with large, firm bladder; 1 with no recorded information on bladder palpation | 1 with large, flaccid bladder | 0 | |
| Abnormal – localization of lesion and with type of bladder | Spinal cord S1–S3: 1 with large, firm bladder that was difficult to express Spinal cord L4–S2: 1 with normal bladder |
Thalamocortex: 1 with small and firm bladder | Suspected hepatic encephalopathy (altered mental state but otherwise normal neurologic examination): 1 with normal bladder |
No information regarding the bladder size and/or the ability to manually express the bladder was recorded in the medical files of 6/18 cats. Abnormal findings of the neurologic examination and bladder type are reported but were not linked to urinary incontinence
A complete neurologic examination was recorded for 9/18 patients (50%). Only 5/9 (55%) cats had neurologic deficits: 4/5 (80%) of these patients’ deficits deemed not to be associated with UI at the time of the examination and 1/5 cats had signs compatible with hepatic encephalopathy, suspected to be associated with UI.
Diagnostic tests
The diagnostic tests performed are summarized in Table 5. Each diagnostic test was retrospectively classified into whether it revealed significant abnormalities aiding in the diagnosis or allowed identification of the underlying cause of UI.
Table 5.
Diagnostic tests and their utility in cats with urinary incontinence (UI) related to a non-neurologic cause, depending on their anatomic location (urethra, bladder or other)
| Test | Number of cats in which the test was performed (n = 18) | Number of cats in which the test revealed significant abnormalities (n = 18) | Number of cats in which the test identified an underlying cause for UI (n = 18) | Definitive diagnosis | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Total | Urethra | Bladder | Other | Total | Urethra | Bladder | Other | Total | Urethra | Bladder | Other | ||
| Serum biochemistry | 17 (94) | 12 (67) | 4 (22) | 1 (6) | 10 (55) | 7 (39) | 2 (11) | 1 (6) | 0 | 0 | 0 | 0 | – |
| Urinalysis | 14 (78) | 9 (50) | 4 (22) | 1 (6) | 6 (33) | 3 (17) | 3 (17) | 0 | 1 (6) | 1 (6) | 0 | 0 | Strong suspicion of neoplastic cells (urethral neoplasia) (1) |
| Urine culture | 10 (55) | 5 (28) | 4 (22) | 1 (6) | 6 (33) | 3 (17) | 3 (17) | 0 | 3 (17) | 0 | 3 (17) | 0 | UTI (3) |
| Abdominal ultrasound | 13 (72) | 8 (44) | 4 (22) | 1 (6) | 8 (44) | 4 (22) | 3 (17) | 1 (6) | 3 (17) | 2 (6) | 0 | 1 (6) | Portosystemic shunt (hepatic encephalopathy) (1), neoplastic urethral mass (1), uroliths (1) |
| Abdominal radiographs | 6 (33) | 5 (28) | 1 (6) | 0 | 3 (17) | 3 (17) | 0 | 0 | 1 (6) | 1 (6) | 0 | 0 | Uroliths (1) |
| Contrast cystourethrogram | 7 (39) | 5 (28) | 2 (11) | 0 | 6 (33) | 5 (28) | 1 (6) | 0 | 4 (22) | 4 (22) | 0 | 0 | Urethral stricture (4) |
| Cystoscopy | 3 (17) | 3 (17) | 0 | 0 | 3 (17) | 3 (17) | 0 | 0 | 3 (17) | 3 (17) | 0 | 0 | Urethral stricture (2), foreign body (1) |
| Bladder wall biopsy | 1 (6) | 0 | 1 (6) | 0 | 1 (6) | 0 | 1 (6) | 0 | 1 (6) | 0 | 1 (6) | 0 | Encrusted cystitis (1) |
Data are n (%)
UTI = urinary tract infection
Serum biochemistry was performed in 17/18 cats (94%). Azotemia (creatinine >140 µmol/l) was present in 8/17 patients (two cats from the bladder group and six from the urethral group). Pre- and postprandial bile acids were evaluated and elevated in 1/17 cats; this cat had a portosystemic shunt identified on ultrasonography (later diagnosed with hepatic encephalopathy). Hyperkalemia (5.39 mmol/l; reference interval 3.6–5.30) was present in 1/17 cats (this patient had urethral obstruction secondary to feline idiopathic cystitis).
Urine culture was performed in 10/18 cats (56%); 4/10 (40%) were positive. Bacteria identified were Klebsiella pneumoniae (1/4), Proteus mirabilis (1/4) and Staphylococcus species (2/4). Urinalysis was reported in 14/18 patients (78%). Inflammatory urine sediment (significant leukocyturia, hematuria and proteinuria) was present in five patients. Bacteriuria was associated with an inflammatory urine sediment, as well as lower urinary tract signs in three cats (UTI was the diagnosed in these patients). One patient had subclinical bacteriuria (foreign body). There was a strong suspicion of neoplastic cells in the sediment of 1/14 cats, in which urethral neoplasia was later confirmed.
Abdominal ultrasound was performed in 13 patients (72%). Within the urethral group, significant abnormalities included signs of lower urinary tract obstruction (proximal urethral dilatation) in two patients, urethral and bladder stones in one cat (as well as an extrahepatic shunt), a marked thickening of the urethra–vesical junction extending from the proximal urethra consistent with a neoplastic mass in one cat. Within the bladder group, noteworthy anomalies of the urinary tract included bladder wall thickening (2/13; 1/2 with encrusted cystitis) and significant bladder distension with no mechanical urethral obstruction visualized (1/13). An extrahepatic shunt was suspected in 2/13 cats (1/2 with current ammonium urate stones and 1/2 with current hepatic encephalopathy).
Abdominal radiographs were performed in 6/18 patients. Significant radiographic findings were recorded within the urethral group only and included significant bladder overdistension (2/6) and urolithiasis (1/6). All patients with abdominal radiographs also had an abdominal ultrasound.
Minimally invasive procedures were undertaken in 10 cats (55%) as part of the diagnostic work-up (8/10 cats with urethral disorders and 2/10 cats with bladder disorders). Cystoscopy was performed in female cats (3/10) and contrast cystourethrography in male cats (7/10). Cystoscopic abnormalities noted were a fibrous band at the urethra-vesical junction creating a stricture in one patient, a severe stricture at the urethra–vesical junction measuring 7 mm in length with a 1 mm in diameter lumen in one patient and an agglomerate of hair and other unidentified material in the clitoral fossa with no other abnormalities of the lower urinary tract in one patient. Contrast cystourethrography demonstrated a stricture in 4/7. In these four patients, the urethral strictures were located: 2 cm from the end of the distal urethra, at the level of the pelvic inlet, distal to the pelvis and in the distal third of the urethra. No structural abnormalities were identified in 2/7 patients (one of which was suspected to have detrusor atony in the end). In one patient with encrusted cystitis, the only abnormality was a thickened and irregular bladder wall. The examination could not be performed in two cats as a stricture at the perineal urethrostomy site was found and prevented urethral catheterization. A cystoscopy was converted to a contrast cystourethrogram in one male cat with a perineal urethrostomy for the same reason.
Management and outcome of urinary incontinence
Outcome was available in 17/18 cats (94%) between 0 and 1 week for one cat (euthanized), between 1 week and 3 months for six cats and >3 months for 10 cats.
Table 6 shows detailed information regarding management for 16 cats and outcome (including posology of drugs). Twelve cats underwent therapeutic interventions.
Table 6.
Final diagnosis, management (medical and interventional therapies) and outcome in 18 cats with non-neurologic incontinence
| Age (years) | Breed | Sex | Tentative diagnosis | Procedure | UI treatment and associated procedures | Outcome |
|---|---|---|---|---|---|---|
| 9 | DSH | M | Urethral obstruction (suspected FIC and urethral spasm) | Short term: euthanasia | ||
| 9.5 | DSH | F | Partially obstructive proximal urethral carcinoma | Fluoroscopic-guided percutaneous cystostomy tube placement | Meloxicam (0.05 mg/kg q24h PO) for 10 days. Cystotomy tube drainage q12h | Mid-term: no complication regarding cystotomy tube. Natural death (unknown cause) |
| 1.5 | Highland Lynx | M | Urethral stricture at perineal urethrostomy site | Surgical revision of perineal urethrostomy | Prazosin* (0.5 mg total q12h PO) for 7 days, gabapentin (8.3 mg/kg q12h to q8h PO) † for 2 weeks, meloxicam (0.05 mg/kg) ‡ for 3 days | Mid-term: resolution of UI. Episode of UTI |
| 16.5 | DSH | F | Suspected secondary to UTI | Acid clavulanic/amoxicillin (16.6 mg/kg q12h PO) § for 2 weeks, gabapentin (10 mg/kg q12h) † for 7 days, dantrolene (0.5 mg/kg q8h) † for 7 days | Unknown – lost to follow-up | |
| 1.5 | Manx | M | Urethral stricture at distal third of urethra and suspected secondary detrusor atony | Declined (urethral balloon dilatation and stent placement) | Bethanechol (0.5 mg/kg q8h PO) ¶ for 2 months, prazosin (0.5 mg total q8h PO)* switched to tamsulosin (50 µg total q24h PO) ∞ for 2 months | Mid-term: partial improvement of UI Long term: persisting UI |
| 4.5 | DSH | M | Encrusted cystitis (Proteus mirabilis) and suspected concomitant detrusor atony | Bethanechol (1.34 mg/kg q8h PO) ¶ for 2 weeks, tamsulosin (0.40 mg total q12h PO) † for 4 weeks, prednisolone (0.65mg/kg total PO) † for 2 weeks, clavulanic acid/amoxicillin (16.7 mg/kg q12h PO) § for at least 4 weeks | Short term: partial improvement with now spontaneous micturition Mid-term: persisting UI Long term: euthanasia due to complete urethral obstruction |
|
| 12 | DSH | M | Urethral obstruction due to urate stones and extrahepatic portosystemic shunt | Percutaneous cystolithotomy | Allopurinol (3.75 mg/kg q24h PO) # ad libitum, buprenorphine (0.015 mg/kg q12h SL) † for 5 days, clavulanic acid/amoxicillin (15.6 mg/kg q12h PO) § for 7 days, meloxicam (0.05 mg/kg q24h PO) ‡ for 3 days | Mid-term: no stone recurrence |
| 3.5 | DSH | M | Detrusor atony (suspected due to past urethral obstruction based on history) | Fluoroscopic-guided percutaneous cystostomy tube placement | Twice-daily cystotomy tube drainage | Long term: pulled cystostomy tube out twice in one month and was euthanized after 1 year and 1 month |
| 3 | DSH | F | Fibrous band at the urethra–vesical junction creating a stricture, possible secondary detrusor atony | Stricture ruptured by passage of cystoscope | Meloxicam (0.05 mg/kg q24h PO) ‡ for 3 days, buprenorphine (0.013 mg/kg q12h–q8h SL)† for 5 days, clavulanic acid/amoxicillin (13.3 mg/kg q12h PO) § for 5 days | Mid-term: partial improvement. Trial of bethanechol (0.5 mg/kg q8h PO for 2 weeks) ¶ then phenylpropanolamine (1 mg/kg q8h PO for 2 weeks)*. Development of fecal incontinence. Long term: euthanasia |
| 7 | DSH | M | Urethral stricture at perineal urethrostomy site | Surgical revision of perineal urethrostomy | Bethanechol (0.95 mg/kg q8h PO) ¶ for 2 weeks, buprenorphine (0.013 µg/kg q8h PO)† for 5 days | Short term: pollakiuria, partial improvement of UI Mid-term: UTI (Escherichia coli, Enterococcus species) causing pollakiuria; 1 month post-surgery – resolution of UI |
| 4 | DSH | F | Urethral stricture at urethra–vesical junction | Fluoroscopic-guided balloon dilatation of the stricture | Prednisolone (1 mg/kg q24h 1 week then 0.5 mg/kg PO for 1 week) † , prazosin (0.5 mg total q12h PO)* for 2 weeks, buprenorphine (0.016 mg/kg q8h PO) † for 3 days, clavulanic acid/amoxicillin (12.5 mg/kg q12h PO) § for 7 days | Mid-term and long term: resolution of UI |
| 0.5 | Manx | M | Penile urethral necrosis of unknown origin with urethritis possibly due to multiple anterior catheterizations | Perineal urethrostomy | Bethanechol (0.73 mg/kg q12h PO) ¶ for 14 days, prazosin (0.5 mg total q12h PO)* for 7 days, buprenorphine (0.018 mg/kg q12h SL) † for 5 days, meloxicam (0.05 mg/kg q24h PO)‡ for 3 days | Mid-term: persisting UI (no spontaneous voiding) |
| 9 | DSH | F | Hepatic encephalopathy secondary to an extrahepatic portosystemic shunt | Metronidazole (8 mg/kg q12h PO) † ad libitum, lactulose (38.8 mg/kg q12h PO) † ad libitum | Mid-term: resolution of UI Long term: euthanasia (deterioration of general state) |
|
| 10 | DSH | M | Detrusor atony suspected secondary to urethral outlet obstruction of unknown cause | Urinary catheterization for 24 h | Bethanechol (0.4 mg/kg q12h) ¶ for 7 days, prazosin (0.25 mg total q12h PO)* for 10 days, buprenorphine (0.015 mg/kg q12h–q8h SL)† for 3 days | Long term: resolution of UI, episode of recurrence of UI suspected secondary to FIC |
| 20 | DSH | M | Suspected secondary to UTI | Clavulanic acid/amoxicillin (9.8 mg/kg q12h PO) § for 2 weeks | Long term: persisting UI, euthanasia | |
| 3 | DSH | F | Hair agglomerate and other unidentified material in the clitoral fossa | Removal of foreign body by cystoscopy | Prazosin (0.05 mg/kg q12h PO)*, buprenorphine (0.016 mg/kg q12h SL) † for 5 days, amoxicillin (75 mg total or 8 mg/kg q12h PO – obese cat) † for 3 weeks | Short term: improvement of UI and pollakiuria Long term: marked improvement – two episodes of recurrence of UI suspected secondary to UTI |
| 5 | DSH | M | Severe urethral stricture at perineal urethrostomy site and suspected secondary detrusor atony | Prepubian urethrostomy | Phenoxybenzamine (2.5 mg: 0.53 mg/kg q12h PO)** for 7 days, bethanechol (0.26 mg/kg q12h PO) ¶ for 7 days, clavulanic acid/amoxicillin (13.3 mg/kg q12h PO) § for 14 days | Long term: resolution of UI |
| 15 | DSH | M | Distal urethral stricture and suspected secondary detrusor atony | Fluoroscopic-guided balloon dilatation then placement of two balloon-mounted urethral stents | Prazosin (0.5 mg q12h PO)* for 7 days, bethanechol (0.8 mg/kg q12h PO) ¶ for 7 days, dexamethasone (0.08 mg/kg q24h)† for 7 days, tramadol (2 mg/kg q12h PO)† for 7 days | Long term: resolution of UI. One episode of hematuria following stent displacement |
Short term (0–1 week), mid-term (1 week to 3 months), long term (>3 months)
Teva-prazosin (TEVA Canada)
Unavailable in medical data
Metacam (Boehringer Ingelheim)
Clavaseptin (Vetoquinol) or Clavamox (Zoetis)
Duvoid (Paladin Labs)
Sandoz Tamsulosin (Sandoz Canada)
Allopurinol (Summit Medical Group)
Phenoxybenzamine Gentes (Gentès & Bolduc Pharmaciens)
UI = urinary incontinence; DSH = domestic shorthair; M = male; F = female; UTI = urinary tract infection; SL = sublingual; FIC = feline idiopathic cystitis
Techniques used to treat urethral strictures varied according to the site of stricture. Two cats with a stricture at their PU site underwent a surgical revision of their previous urethrostomy. One cat with a severe stricture at the PU site had a prepubic urethrostomy performed. Two cats had fluoroscopic-guided balloon dilatation of their stricture. One of these patients also had two balloon-mounted urethral stents placed under fluoroscopic guidance as there was evidence of a persistent stricture distal to the first stent. In two cats, postoperative management included treatment of suspected detrusor atony (bethanechol). Short-term steroids were prescribed in the two cats with fluoroscopic-guided balloon dilatation. Incontinence completely resolved in these five patients (>3 months). UTI was reported in 1/5 cats between the time period of 1 week to 3 months.
However, UI persisted in two cats with urethral strictures despite initial partial improvement. One of these cats had a thin stricture ruptured by passage of the cystoscope. UI persisted despite a trial of bethanechol and then phenylpropanolamine, and fecal incontinence appeared after 3 months. This cat was euthanized. A neurological cause was suspected to have been present but undiagnosed. The other cat was managed medically (prazosin and bethanechol) because of owner financial restrictions. A partial improvement after a switch from prazosin to tamsulosin was noted (resolution of dribbling while walking). The patient was then lost to follow-up.
Three cats that had their urethral obstruction alleviated presented complete resolution of UI (two cats) or marked improvement (one cat). Resolution of UI was recorded in one cat following a percutaneous cystolithotomy to remove urate urolithiasis and one cat with a 24 h urinary catheterization for recent bladder atony. Marked improvement was reported in one cat with a foreign body removed through cystoscopy. Recurrence of UI during episodes of UTI were described after 3 months for two of these cats. In contrast, UI persisted in another patient despite relief of obstruction (penile necrosis treated with perineal urethrostomy). Neurologic deficits (suspected Manx syndrome) that were initially not thought to be the cause of UI by board neurologist were present at admission for this cat.
Fluoroscopic-guided percutaneous cystostomy tubes were placed in two cats: one with urethral carcinoma and the second for severe detrusor atony non-responsive to medical treatment. Meloxicam was also prescribed to the patient with a urethral carcinoma. Both cats had their bladders drained twice a day by the owners. The cat diagnosed with a neoplasia died of unknown causes 2 months after tube placement, but no complications were noted regarding the cystostomy tube. The other patient pulled its cystostomy tube out twice and was euthanized 1 year and 1 month after tube placement.
The patient with hepatic encephalopathy secondary to a portosystemic shunt was managed medically with metronidazole and lactulose ad libitum. UI resolved completely, but it was euthanized 5 months later owing to overall deterioration.
One cat with encrusted cystitis was treated with antibiotics (amoxicillin/clavulanic acid) for 2 months, an alpha-1 antagonist (tamsulosin) and management of detrusor atony (bethanechol) for 2 weeks. Prednisolone was administered at an anti-inflammatory dose for 2 weeks. Partial improvement was noted initially; however, incontinence reoccurred along with urethral obstruction which led to euthanasia. Similarly, one cat with UI suspected to be secondary to a UTI (treated with amoxicillin/clavulanic acid) did not improve despite treatment. It was euthanized 4 months later.
Discussion
UI is rare in cats, as shown by the small number of cases presented to a veterinary teaching hospital over a 10-year period. In this study, a neurologic cause of UI was identified in almost half of the cats (17/35 [48%]) with congenital anomalies (4/17 [23%]) and trauma (7/17 [41%]) being the most frequently identified. In another retrospective study, similar conclusions were drawn as 18/45 cats (40%) with UI were diagnosed with a spinal cord disease (9/18 [50%] trauma and 4/18 [22%] congenital anomalies) over an 11-year period. 7 No difference in signalment was present in patients presenting neurologic and non-neurologic UI in our study. Moreover, in a recent retrospective study, cats with spinal cord disease had, in greater proportion, other concurrent neurologic signs than cats with urethral or bladder lesion. 7 A full neurologic examination should therefore always be performed in any cat presenting with UI.
Urethral disease was the second most common cause of UI (12/35 cats [34%]). A recent retrospective study reported similar results with 17/45 (38%) cats had urethral disorders. More particularly, in our study, all 12 cats presented mechanical urethral obstruction. This is in marked contrast to dogs in which common causes of UI were acquired USMI (62% of dogs) and ectopic ureter (23% of dogs) in a study of 563 dogs. 31 This highlights an important difference between dogs and cats as no cases of acquired USMI or ectopic ureter were reported in this study, and case studies of these are scarce in the literature.7,8,11,15,16 The reason behind the difference in these two species is unknown; however, anatomic differences may be responsible. Congenital USMI could be more common in cats than acquired USMI and seems usually associated with other congenital abnormalities (urethral hypoplasia or pelvic bladder).11,32 However, further studies with larger populations of cats are needed to establish prevalence and confirm this observation.
In this study, urethral strictures were the most common cause of urethral obstruction (7/12 patients [58%]) with 3/7 strictures arising from complications of perineal urethrostomy and 4/7 of unknown origin. According to a prospective study, stricture following perineal urethrostomy depends on urethral orifice diameter and is more likely if the largest urinary catheter size that can be inserted immediately postoperatively is inferior to 8 Fr. 33 Other causes of urethral obstruction were inflammation (2/12), neoplasia (1/12), urolithiasis (1/12) and foreign body (1/12). Similar results were reported in a recent retrospective study including 45 cats, where six cats presented strictures and 12 cats had other causes of urethral obstruction.
Cats that were diagnosed with urethral outlet obstructions generally had a good prognosis when an interventional procedure was performed. Complete resolution of UI was noted in seven cats (five cats with strictures, one cat with urolithiases, one cat following urethral catheterization for bladder atony). Single case reports show similar excellent outcomes for balloon-dilated strictures.21,22 Partial improvement of UI was noted for one cat with a foreign body removed via cystoscopy. No medication after 3 months was necessary in any of these cases. In another study, half of the cats undergoing surgery for a potentially reversible causing UI showed favorable outcomes. 7 In contrast, two cats with untreated strictures continued to present UI, despite medical management of suspected underlying detrusor atony. Surprisingly, the time of onset of UI was variable ranging from 1 day to 1 year (two cats presented UI for <5 days, one for 12 days, one for 1 month, two for 3 months, two for 1 year). The ability to resolve UI did not appear to be linked with the length of onset. A prospective study would be needed to correctly determine if prognosis following an intervention is influenced by the duration of UI.
Disorders affecting the bladder were uncommon in this study (5/35 [14%]), in comparison to recent retrospective studies (9/45 [20%]). 7 Unfortunately, because of the small number of cases, statistical analysis was not undertaken to compare differences in signalment and in clinical presentation between cats with a urethral lesion and a bladder lesion. A recent retrospective study showed urethral disease to be significantly more common in male cats and cats with bladder disorders were significantly older. 9
Diagnostic tests differed depending on the patient, the attending veterinarian and the owners. The usefulness of various diagnostic tests was retrospectively evaluated. Contrast cystourethrography and cystoscopy helped identify the underlying etiology in 8/10 patients in which it was performed. The majority of cats undergoing this examination were in the urethral group (8/10), and 6/10 had a bladder that was difficult to express, suggesting the clinical presentation might have oriented the attending veterinarian towards a urethral disorder. These diagnostic tests were performed following ultrasound in six patients. Abdominal ultrasound, however, was the most commonly performed test, but only lead to a diagnosis in 3/13 patients (urethral neoplasia, urolithiasis and portosystemic shunt in a cat with suspected hepatic encephalopathy). In our study, cystoscopy was performed in female cats, while cystourethrography was performed in male cats. Retrograde urethrocystoscopy is difficult in male cats given their small penile urethra and the size of the cystoscopes available. Antegrade cystoscopy through a percutaneous approach could be performed in male cats as an alternative. 34 In one cat, retrograde catheterization was not possible because of a stricture at the perineal urethrostomy site. Fluoroscopically guided percutaneous antegrade urethral catheterization could have been performed in this patient to inject contrast and gain urethral access as an alternative method to confirm the diagnosis. 35
Several limitations were present in this study due to the assessment of cases by several attending veterinarians from different departments (internal medicine, surgery, intensive care unit, general practice, neurology); hence, there was a heterogeneity in the evaluation of cases and completion of medical files. In addition, with the relatively small study population and the lack of a standardized evaluation, it becomes difficult not only to associate the clinical signs to the definitive diagnosis, but also to compare cases and groups based on the anatomic lesion and to draw definitive conclusions on recommended diagnostic tests, prognosis and effect of medical management. Furthermore, many cats did not undergo the recommended diagnostic tests because of owners’ financial restrictions.
Conclusions
Almost half of the cats with UI had an underlying neurologic origin with no difference in signalment vs cats with a non-neurologic origin. Once neurologic causes have been excluded, urethral obstruction should be considered. In cats with urethral disorders, the most helpful diagnostic tests to identify anatomic anomalies are cystoscopy and/or contrast cystourethrography. Prognosis is good if a procedure to correct the underlying cause can be undertaken. This highlights that feline UI is very different from dogs.
Acknowledgments
The authors thank Guy Beauchamp for statistical analysis.
Footnotes
Accepted: 28 June 2021
The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding: The authors received no financial support for the research, authorship, and/or publication of this article.
Ethical approval: This work involved the use of non-experimental animals only (including owned or unowned animals and data from prospective or retrospective studies). Established internationally recognized high standards (‘best practice’) of individual veterinary clinical patient care were followed. Ethical approval from a committee was therefore not necessarily required.
Informed consent: Informed consent (either verbal or written) was obtained from the owner or legal custodian of all animal(s) described in this work (either experimental or non-experimental animals) for the procedure(s) undertaken (either prospective or retrospective studies). No animals or humans are identifiable within this publication, and therefore additional informed consent for publication was not required
ORCID iD: Isabelle Mérindol 
https://orcid.org/0000-0002-2919-3681
References
- 1. Labato MA, et al. Pollakiuria, stranguria, and urinary incontinence. In: Ettinger SJ, Feldman EC, Cote E, et al (eds). Textbook of veterinary internal medicine. St Louis, MO: Elsevier, 2017, pp 666–672. [Google Scholar]
- 2. Silverman S, Long CD. The diagnosis of urinary incontinence and abnormal urination in dogs and cats. Vet Clin North Am Small Anim Pract 2000; 30: 427–448. [PubMed] [Google Scholar]
- 3. Borns-Weil S. Inappropriate urination. Vet Clin North Am Small Anim Pract 2019; 49: 141–155. [DOI] [PubMed] [Google Scholar]
- 4. Chew DC, Dibartola SP, Schenck PA. Disorders of micturition and urinary incontinence. In: Chew DC, Dibartola SP, Schenck PA. (eds). Canine and feline nephrology and urology. St Louis, MO: Elsevier Saunders, 2011, pp 409–433. [Google Scholar]
- 5. Lekcharoensuk C, Osborne CA, Lulich JP. Epidemiologic study of risk factors for lower urinary tract diseases in cats. J Am Vet Med Assoc 2001; 218: 1429–1435. [DOI] [PubMed] [Google Scholar]
- 6. Lane IF, Lappin MR. Urinary incontinence. In: Lappin MR. (ed). Feline internal medicine secrets. Phildadelphia, PA: Hanley and Belfus, 2001, p 255. [Google Scholar]
- 7. Lonc KM, Kaneene JB, Carneiro PAM, et al. Retrospective analysis of diagnoses and outcomes of 45 cats with micturition disorders presenting as urinary incontinence. J Vet Intern Med 2020; 34: 216–226. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8. Pisu MC, Veronesi MC. Effectiveness of deslorelin acetate subcutaneous implantation in a domestic queen with after-spaying urinary incontinence. J Feline Med Surg 2014; 16: 366–368. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 9. David G, Rajendran EI. The after effects of spaying in bitches and cats. Cheiron 1980; 9: 193–195. [Google Scholar]
- 10. Barsanti JA, Downey R. Urinary incontinence in cats. J Am Anim Hosp Assoc 1984; 20: 979–982. [Google Scholar]
- 11. Wilson KE, Berent AC, Weisse CW. Use of a percutaneously controlled hydraulic occluder for treatment of refractory urinary incontinence in three female cats. J Am Vet Med Assoc 2016; 248: 544–551. [DOI] [PubMed] [Google Scholar]
- 12. Bartges JW, Callens AJ. Congenital diseases of the lower urinary tract. Vet Clin North Am Small Anim Pract 2015; 45: 703–719. [DOI] [PubMed] [Google Scholar]
- 13. Baines SJ, Speakman AJ, Williams JM, et al. Genitourinary dysplasia in a cat. J Small Anim Pract 1999; 40: 286–290. [PubMed] [Google Scholar]
- 14. Holt PE. Surgical management of congenital urethral sphincter mechanism incompetence in eight female cats and a bitch. Vet Surg 1993; 22: 98–104. [DOI] [PubMed] [Google Scholar]
- 15. Fournet A, Maurey C, Decambron A, et al. Treatment of urinary incontinence in a cat with genitourinary dysplasia using an urethral sphincter occluder. J Small Anim Pract 2021; 62: 391–396. [DOI] [PubMed] [Google Scholar]
- 16. Holt P, Gibbs C. Congenital urinary incontinence in cats: a review of 19 cases. Vet Rec 1992; 130: 437–442. [DOI] [PubMed] [Google Scholar]
- 17. Ghantous SN, Crawford J. Double ureters with ureteral ectopia in a domestic shorthair cat. J Am Anim Hosp Assoc 2006; 42: 462–466. [DOI] [PubMed] [Google Scholar]
- 18. Di Mauro FM, Singh A, Reynolds D, et al. Combined use of intravesicular ureteroneocystostomy techniques to correct ureteral ectopia in a male cat. J Am Anim Hosp Assoc 2014; 50: 71–76. [DOI] [PubMed] [Google Scholar]
- 19. Brace MA, Weisse C, Berent A. Preliminary experience with stenting for management of non-urolith urethral obstruction in eight cats. Vet Surg 2014; 43: 199–208. [DOI] [PubMed] [Google Scholar]
- 20. Shipov A, Zafrany A, Kahana N, et al. Successful balloon expandable stent placement in the management of severe proximal urethral stricture in a cat. Isr J Vet Med 2014; 69: 88–91. [Google Scholar]
- 21. Rincon Alvarez J, Smith V, Broome C. Fluoroscopy-guided balloon dilation of a proximal urethral stricture caused by a urethral membrane in a female cat. JFMS Open Rep 2019; 5. DOI: 10.1177/2055116919867177. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 22. Ruiz-Drebing M, Yap F, Seth M, et al. Membrane-like structure in the urinary bladder neck of a young cat: diagnosis and treatment using balloon dilatation and a balloon-expandable metallic stent. JFMS Open Rep 2017; 3. DOI: 10.1177/205511691773364. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 23. Crowe YC, Child G, Lam R, et al. Congenital block vertebrae and intervertebral disc protrusion in a young cat. JFMS Open Rep 2019; 5. DOI: 10.1177/2055116919868037. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 24. Foster S, Hunt G, Malik R. Congenital urethral anomaly in a kitten. J Feline Med Surg 1999; 1: 61–64. [DOI] [PubMed] [Google Scholar]
- 25. Eisele JG, Jackson J, Hager D. Ectopic ureterocele in a cat. J Am Anim Hosp Assoc 2005; 41: 332–335. [DOI] [PubMed] [Google Scholar]
- 26. Suess RPJ, Martin RA, Moon ML, et al. Rectovaginal fistula with atresia ani in three kittens. Cornell Vet 1992; 82: 141–153. [PubMed] [Google Scholar]
- 27. Buzatto AB, Elias F, Franzoni MS, et al. Long-term survival of a cat with primary leiomyosarcoma of the urinary bladder. Vet Sci 2019; 6: 60. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 28. James DR, Collins D, Johnson PJ, et al. Chronic urinary bladder torsion causing urinary incontinence in a cat. JFMS Open Rep 2015; 1. DOI: 10.1177/ 2055116915603384. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 29. Lappin MR, Barsanti JA. Urinary incontinence secondary to idiopathic detrusor instability: cystometrographic diagnosis and pharmacologic management in two dogs and a cat. J Am Vet Med Assoc 1987; 191: 1439–1442. [PubMed] [Google Scholar]
- 30. Munana KR, Olby NJ, Sharp NJ, et al. Intervertebral disk disease in 10 cats. J Am Anim Hosp Assoc 2001; 37: 384–389. [DOI] [PubMed] [Google Scholar]
- 31. Holt PE. Urinary incontinence in dogs and cats. Vet Rec 1990; 127: 347–350. [PubMed] [Google Scholar]
- 32. Holt PE, Gibbs C. Congenital urinary incontinence in cats: a review. Vet Rec 1992; 130: 436–442. [DOI] [PubMed] [Google Scholar]
- 33. Segal U, Shani J, Zemer O, et al. Evaluation of urethral orifice cross-section dimensions following perineal urethrostomy in male cats. J Small Anim Pract 2020; 61: 475–479. [DOI] [PubMed] [Google Scholar]
- 34. Cruciani B, Vachon C, Dunn M. Removal of lower urinary tract stones by percutaneous cystolithotomy: 68 cases (2012–2017). Vet Surg 2020; 49: O138–O147. [DOI] [PubMed] [Google Scholar]
- 35. Holmes ES, Weisse C, Berent AC. Use of fluoroscopically guided percutaneous antegrade urethral catheterization for the treatment of urethral obstruction in male cats: 9 cases (2000–2009). J Am Vet Med Assoc 2012; 241: 603–607. [DOI] [PubMed] [Google Scholar]