Guarded long-term prognosis in male cats with urethral obstruction

Retrospective evaluation of the prevalence and risk factors associated with red blood cell transfusions in cats with urethral obstruction (2009-2019): 575 cases

OBJECTIVE

To evaluate the prevalence of red blood cell (RBC) transfusions and factors associated with the need for transfusion in cases of feline urethral obstruction (FUO). Secondarily, to compare survival to discharge in cats receiving an RBC transfusion versus those that did not.

DESIGN

Retrospective, multi-institutional study from 2009 to 2019.

SETTING

Four university teaching hospitals.

ANIMALS

Six hundred twenty-two total occurrences of FUO in 575 cats.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Medical records were retrospectively reviewed for pertinent information. The overall prevalence of severe anemia (PCV < 0.20 L/L [<20%]) at presentation was 1.0% (6/622). The prevalence of RBC transfusions during hospitalization was 2.1% (13/622). Cats that received an RBC transfusion weighed significantly less than those that did not (4.9 vs 5.8 kg; P = 0.034) and had a lower PCV at presentation (0.30 L/L [30%] vs 0.41 L/L [41%]; P < 0.001). Hospitalization time (240 vs 72 h) and indwelling urinary catheter time (168 vs 48 h) were significantly longer in cats receiving a transfusion compared with those that did not (P < 0.001). Creatinine concentrations were not significantly associated with transfusion administration, while BUN was higher in cats receiving a transfusion (15.35 mmol/L [43 mg/dL] vs. 11.78 mmol/L [33 mg/dL]; P = 0.043). Transfusion rates were significantly higher in cats undergoing perineal urethrostomy (5.5%) compared with those that did not undergo surgery (0.97%; P < 0.001). The overall survival to discharge rate was 96%. Cats not receiving an RBC transfusion were significantly more likely to survive to discharge than those that did (odds ratio: 14.7, 95% confidence interval: 1.8-37; P < 0.001).

CONCLUSIONS

FUO is rarely associated with severe anemia and the need for RBC transfusions. In this study, cats receiving an RBC transfusion were less likely to survive to discharge; therefore, requiring a blood transfusion may be associated with a worse prognosis. In addition, the need for surgical intervention was associated with a higher prevalence of RBC transfusions.

Effect of tamsulosin on urethral tone in healthy male cats

OBJECTIVES

Alpha-adrenergic antagonists are commonly used to prevent recurrent urethral obstruction in cats with mixed reports of efficacy. No published data on tamsulosin use in cats are available. The objective of this study was to measure changes in urodynamic parameters and blood pressure in five healthy male cats before and after administration of tamsulosin orally for 4 and 10 days.

METHODS

Five young healthy adult male cats from a research colony were administered tamsulosin at 0.1 mg/cat PO q24h for 10 days. Urethral pressure profile and blood pressure measurements were performed before treatment and approximately 6 h after treatment on days 4 and 10. Maximum urethral closure pressure (MUCP) for the prostatic and penile urethra, functional urethral length (FPL), functional area (FA) and systolic blood pressures were recorded and compared between the time points.

RESULTS

Significant changes in blood pressure on day 4 (121.1 mmHg ± 20.2 mmHg) and on day 10 (112.6 mmHg ± 14.9 mmHg) compared with day 0 (141.1 mmHg± 33.4 mmHg) were not detected (P = 0.18) in anesthetized cats. No significant difference in MUCP, FA or FPL measurements were detected among baseline, day 4 and day 10 of treatment. Hematuria and transient pollakiuria were induced in two cats with 3.5 Fr urethral catheters.

CONCLUSIONS AND RELEVANCE

Tamsulosin at 0.1 mg/cat PO q24h did not induce hypotension in healthy cats. Urodynamic testing performed 6 h after the tamsulosin pill was administered did not detect consistent decreases in urodynamic functions induced by tamsulosin. Repeated catheterization of tom cats with 3.5 Fr catheters may induce significant urethral trauma.

Incidence of feline idiopathic cystitis and urethral obstruction during COVID-19 human movement restrictions in Queensland, Australia

OBJECTIVES

Feline idiopathic cystitis (FIC) and urethral obstruction (UO) are commonly linked to increased stress. The influence of human movement restrictions on their incidence remains undetermined. FIC with or without UO is associated with environmental stress factors. The severe acute respiratory syndrome coronavirus 2 (COVID-19) pandemic restricted human movement and working behaviours. It is unknown if these restrictions increased the risk of FIC or UO in cats.

METHODS

Total cat emergency accessions and transfers between 8 February 2019 and 8 February 2021 at two private hospitals were retrospectively reviewed. Cats were included in the FIC group if they presented with lower urinary tract signs and supporting urinalysis, and were included in the UO group if they presented with UO. Cats with current urinary tract infection, or previous FIC or UO, were excluded. Groups were considered 'pre-COVID-19' between February 2019 and 2020 and 'COVID-19' between February 2020 and 2021. Cases of FIC and UO were compared between COVID-19 and pre-COVID-19 using Fisher's exact test and relative risk (RR) calculations.

RESULTS

The pre-COVID-19 incidence of FIC was 4.3% (63/1477, 95% confidence interval [CI] 0.0332-0.053), non-obstructive FIC was 1.4% (20/1477, 95% CI 0.008-0.020) and UO was 2.9% (43/1477, 95% CI 0.020-0.038). One cat was excluded as obstruction occurred during hospitalisation. The COVID-19 incidence of FIC was 5.4% (113/2081, 95% CI 0.044-0.64), non-obstructive FIC was 2.1% (70/2081, 95% CI 0.014-0.027) and UO was 3.4% (70/2081, 95% CI 0.026-0.042). The risk of non-obstructive FIC (P = 0.122; RR 0.652, 95% CI 0.387-1.096), UO (P = 0.382; RR 0.839, 95% CI 0.577-1.22) or either (P = 0.098; RR 0.773, 95% CI 0.572-1.044) was not significantly higher in the COVID-19 period than the pre-COVID-19 period.

CONCLUSIONS AND RELEVANCE

No clear association between COVID-19 movement restrictions and the incidence of UO or non-obstructive FIC was found within this retrospective population.

Effect of Perineal Urethrostomy on the Length of the Urethra of the Cat: A Cadaveric Study

Perineal urethrostomy in cats is indicated for urethral pathologies located distal to the bulbourethral glands. The description of the bulbourethral glands as the cranial landmark when performing a PU is based on the increased urethral diameter at this location, rather than on an anatomical limitation. This suggests that urethral pathologies cranial to the bulbourethral glands could potentially be treated with PU. At present, the extent to which the pelvic urethra can be mobilized is unknown. Characterization and quantification of the effect of PU on the pelvic urethra is required prior to attempting to define the location of the pelvic urethra, cranial to the bulbourethral glands, which can be exteriorized when performing a PU. Our aim was to characterize and quantify the effect of performing a PU on the location and length of the pelvic urethra.

METHODS

Ten male feline cadavers were used, and four markers were placed on the pelvic urethra via a ventral approach to the peritoneal and pelvic cavities. Two orthogonal radiographic views were acquired prior and subsequent to performing a PU. The distance of each marker to a predefined landmark/origin and the distances of the markers relative to each other were measured on all radiographs.

RESULTS

PU resulted in significant caudal translation of the markers relative to the predefined landmark on all radiographic views; however, PU did not result in a significant change in the distances between the markers.

CONCLUSIONS

Performing a PU results in caudal translation and minimal stretching of the mobilized pelvic urethra.

Pseudomembranous cystitis in cats with presumed or confirmed mineralization: A retrospective study of 26 cases (2016-2021)

BACKGROUND

Pseudomembranous cystitis (PMC) in cats is a recognized disease, but concurrent mineralization is reported rarely and its outcome is poorly described.

HYPOTHESIS AND OBJECTIVES

Describe a population of cats with PMC and the prevalence of concurrent mineralization.

ANIMALS

Twenty-six cats with PMC.

METHODS

Medical records were retrospectively reviewed (January 2016 to December 2021). Cats with an ultrasound diagnosis of PMC were included. Clinicopathologic results, imaging, treatment, and outcome were reviewed.

RESULTS

All cats were male and 21 (80%) were diagnosed with urethral obstruction (UO). Five cats (23.8%) had positive urine culture (Staphylococcus felis, 3/5; Proteus mirabilis, 2/5) with a median urine pH of 8 (range, 6-9). All cats had ultrasonographic changes suggestive of mineralization. On ultrasound examination, 10 cats (38.5%) had pseudomembranes with acoustic shadowing suggestive of mineralization, 15 (57.7%) had changes indicative of ulceration, and 8 (31%) had changes compatible with of a urachal anomaly. Twenty-two cats received medical treatment, 4 underwent surgery (3 percutaneous cystolithotomy, 1 cystotomy). Twenty cats (77%) survived to discharge. Follow-up ultrasound examination indicated resolution of PMC in 6/7 cats, 4 had persistent hyperechoic bladder lining. Five of 12 cats with follow-up had a relapse of lower urinary tract signs.

CONCLUSIONS AND CLINICAL IMPORTANCE

Pseudomembranous cystitis was diagnosed mainly in male cats with UO and imaging findings suggestive of mineralization were present in all cases. Frequent negative urine culture suggests a different etiology than encrusting cystitis related to urease-positive bacteria. Good outcomes can be achieved with medical management.

Successful management of pelvic urethral strictures with balloon dilation in 3 cats

OBJECTIVE

To describe the successful management of pelvic urethral strictures in 3 young cats (1 after perineal urethrostomy, 1 after a third-time urethral obstruction, and 1 with prolonged lower urinary tract signs post-urethral obstruction) using balloon dilation and a short-term, indwelling urethral catheter.

CASE SUMMARIES

A 9-month-old neutered male domestic longhair cat with a urethral obstruction and a suspected congenitally narrowed urethra was treated via perineal urethrostomy. The cat later developed acute kidney injury, multidrug-resistant urinary tract infections, and a pelvic urethral stricture. A second case, a 2.3-year-old neutered male domestic shorthair cat, developed a stricture of the pelvic urethra after multiple obstructions and catheterizations. A third case, a 1.2-year-old neutered male domestic shorthair cat, had persistent and prolonged lower urinary tract signs after treatment for a urinary obstruction. The cat also had an abnormally small urethral opening and was ultimately found to have a proximal urethral stricture. The strictures in all 3 cases were successfully treated with a combination of fluoroscopic-guided balloon dilation and short-term indwelling urethral catheterization while managing any present infection.

NEW OR UNIQUE INFORMATION PROVIDED

To the authors' knowledge, this is the first published case series of successful balloon dilations paired with the use of a short-term indwelling urethral catheter in cats that developed urethral strictures after catheterization due to urinary obstructions. This procedure appears safe and well tolerated and appears to offer a long-term, cost-effective solution to urethral strictures at the level of the pelvis.

Association between the COVID-19 global pandemic and the prevalence of cats presenting with urethral obstruction at two university veterinary emergency rooms

OBJECTIVES

The aim of this study was to investigate a potential association between the COVID-19 pandemic stay-at-home orders and the prevalence of emergency room presentations for urethral obstruction (UO) in feline patients.

METHODS

Medical records and hospital census were retrospectively searched to identify the total number of cats and total number of male cats with UO presenting to two academic veterinary medical centers from 22 March to 10 August in the years 2018 (123), 2019 (137) and 2020 (175). Cats were grouped based on the year of presentation and the proportions of UO cases relative to all cats presenting to the emergency rooms during the same time frame. Absolute (year of interest - reference year) and relative ([year of interest - reference year]/[reference year]) change in prevalence was determined. These were compared for each year using a two-sample z-test.

RESULTS

The absolute and relative prevalence of UO presentations across the combined population increased significantly during the COVID-19 pandemic in comparison with 2018 (2.2% and 59%, respectively; P = 0.0003) and 2019 (1.9% and 48%, respectively; P = 0.0021). For the individual institutions, a significant increase in UO presentations was found for institution A when comparing 2020 with both 2018 (P = 0.0072) and 2019 (P = 0.0073), but not for institution B (P = 0.057 and P = 0.18, respectively). No significant differences were found when 2018 and 2019 were compared across the combined population or within institutions.

CONCLUSIONS AND RELEVANCE

The results of this study demonstrate an increased prevalence of UO during the initial months of the COVID-19 pandemic, which may be related to environmental change and stress imposed by stay-at-home orders.

Retrospective evaluation of the effect of inhalant anesthesia on complications and recurrence rates in feline urethral obstruction

OBJECTIVES

The aim of this study was to evaluate the use of inhalant anesthesia vs sedation for urinary catheter placement in male cats with urethral obstruction. The primary outcome measures were the incidence of complications related to catheterization, the incidence of recurrent urethral obstruction (rUO; both during hospitalization and within 1 year) and survival. The secondary aim of this study was to evaluate the association between baseline serum biochemical concentrations and antispasmodic medications with complications and short-term rUO.

METHODS

We carried out a retrospective review of records from a university teaching hospital from 2009 to 2020. Cats were included if diagnosed with a urinary obstruction, based on the presence of a large, painful and non-expressible bladder, a urinary catheter was placed and hospitalization occurred for a minimum of 24 h. Collected baseline data included age, breed, weight, serum biochemical concentrations and if cats underwent sedation or inhalant anesthesia for urethral catheterization. For the comparison of inhalant anesthesia or sedation, univariate logistic regression was used.

RESULTS

There was no statistically significant difference in complications or the recurrence of obstruction in cats with urethral obstruction that underwent inhalant anesthesia compared with sedation. All serum biochemical concentrations were significantly associated with survival. Decreased serum ionized calcium was found to be statistically significantly associated with higher complication rates (P = 0.0086), as well as short-term recurrence of obstruction (P = 0.004). Increased serum potassium concentrations were found to be statistically significantly associated with the risk of short-term recurrent urethral obstruction (P = 0.0345). No significant difference was found between the use of antispasmodic medications with short-term recurrence.

CONCLUSIONS AND RELEVANCE

No significant difference was found between complications or recurrence rates when comparing the use of inhalant anesthesia to sedation protocols. Baseline serum biochemical data were significantly associated with complications, survival and short-term recurrence rates.

Neutering is not associated with early-onset urethral obstruction in cats

OBJECTIVES

The purpose of this study was to evaluate the correlation between clinical aspects and urethral lesions with reproductive status and age at neutering in obstructed male cats.

METHODS

All cats with compatible signs of urethral obstruction (UO) treated at the Veterinary Hospital of the Federal Rural University of Pernambuco from 2019 to 2021 were divided into three groups according to their reproductive status: intact; prepubertal neutered; and post-pubertal neutered. Cats with compatible signs of UO were selected for further analysis. Age, clinical signs, age at neutering and age of the first obstructive event were documented. Cats with recurrent obstructive urinary signs or urethral trauma that made catheterization impossible were referred for perineal urethrostomy. The morphology of the excised penises was assessed by histopathological analysis.

RESULTS

Of 84 cats with signs of UO included in this study, 28.6% were classified as intact, 28.6% as prepubertal neutered and 42.8% as post-pubertal neutered. Intact cats had a significantly earlier onset of UO compared with prepubertal and post-pubertal neutered cats, as seen by the age at obstruction (3.6 vs 5.7 and 5.5 years, respectively). Similar clinical signs and histopathological lesions were observed in all groups. The main clinical signs observed were stranguria, hematuria and pollakiuria. All cats had some degree of injury in the penile urethra. The most common lesions were hemorrhage, fibrosis and congestion.

CONCLUSIONS AND RELEVANCE

It appears that intact cats had an earlier onset of UO than neutered cats, regardless of age at neutering. Urethral histopathological lesions and clinical signs were similar in both groups. Pediatric neutering represents a useful tool in the control of abandoned and stray animals and the consequent dissemination of zoonoses, thus having a positive impact on public health.

Treatment strategies for hyperkalemia secondary to urethral obstruction in 50 male cats: 2002-2017

OBJECTIVES

The aims of this study were: to describe the potassium-lowering treatment strategies used to manage moderate-to-severe hyperkalemia in male cats with urethral obstruction (UO); to determine how much dextrose was required per unit of insulin to prevent hypoglycemia; to determine whether early initiation of a dextrose continuous rate infusion (CRI) prevented hypoglycemia; and to determine whether in-hospital mortality was associated with presenting plasma potassium concentration ([K⁺]).

METHODS

The medical records of male cats presenting with a [K⁺] ⩾7.0 mEq/l due to UO that had another [K⁺] measured within 6 h were reviewed retrospectively. All [K⁺] values within the first 6 h, blood glucose concentrations, treatments for hyperkalemia and survival to discharge were recorded. Analyses were performed to test for associations between dextrose:insulin ratios or method of dextrose administration and the development of hypoglycemia; and for presenting [K⁺] and mortality. Normally distributed groups of continuous data were compared with a t-test and categorical data were compared with a Fisher's exact test.

RESULTS

Fifty cats were included. Mean presenting [K⁺] was 8.9 ± 1.0 mEq/l, while the mean final [K⁺] within 6 h was 6.6 ± 1.4 mEq/l. Forty-two (84%) cats were treated with intravenous fluids and 40 (80%) were treated with dextrose and insulin. Median dextrose:insulin ratio was 2 g/u (range 0.4-100). No dextrose:insulin ratio was found to protect against hypoglycemia, and 3/8 cats that became hypoglycemic had received ⩾2 g dextrose per unit of insulin. There was no association between the early initiation of a dextrose-containing CRI and avoidance of hypoglycemia. No association was found between presenting [K⁺] and mortality.

CONCLUSIONS AND RELEVANCE

While no specific dextrose:insulin ratio was found to protect against hypoglycemia, there is evidence that the commonly recommended dextrose:insulin ratio of 2 g/u may be inadequate in preventing hypoglycemia in every cat. Severity of hyperkalemia was not associated with mortality.

Prevalence, Risk Factors, Pathophysiology, Potential Biomarkers and Management of Feline Idiopathic Cystitis: An Update Review

Feline idiopathic cystitis is a widespread disease in small animal clinics, which mainly presents with urinary signs like dysuria, stranguria, hematuria, pollakiuria, and periuria. The etiopathogenesis of the disease may involve interactions between the environmental stressors, neuroendocrine system and bladder of affected cats. Diagnostic biomarkers have not been tested in clinical studies though they are theoretically feasible, and since the clinical signs of the disease assemble those of other feline lower urinary diseases, its diagnosis is a procedure of exclusion. The primary treatment of the disease is long-term multimodal environmental modification (or enrichment) while anti-anxiety drugs and nutritional supplements are recommended for chronic recurrent cases. Still, many medicines need to be evaluated for their efficacy and safety. This review aims to provide readers with a comprehensive understanding of feline idiopathic cystitis by summarizing and updating studies concerning the prevalence, risk factors, etiological hypotheses, diagnostic procedures, possible treatments, and prognosis of the disease.

Occurrence and clinical management of urethral obstruction in male cats under primary veterinary care in the United Kingdom in 2016

Background

Urethral obstruction (UO) has a negative effect on welfare of cats.

Objectives

This study aimed to determine incidence, case management, and outcomes of UO in cats in primary‐care practice in the United Kingdom.

Animals

All male cats under veterinary care within the VetCompass database in 2016.

Methods

A retrospective cohort study was performed. The electronic records of all male cats with a clinical note during the study period were searched for UO cases and were manually reviewed for inclusion. Additional demographic and clinical information were extracted on cases.

Results

From the study cohort of 237 825 male cats, there were 1293 incident cases. The estimated UO incidence risk during 2016 was 0.54 (95% CI: 0.51‐0.57). Demographic and clinical data were available for 1108 cases. Antibiotics were administered to 641/1108 (57.9%) cases. Overall repeat catheterization rate was 253/854 (29.6%). Repeat catheterization at 48 hours was less frequent in patients with indwelling catheters (10.1%) vs those that had a catheter placed and then immediately removed (14.8%; P = .04). Death during a UO episode was 329/1108 (29.6%), and 285/329 (88.0%) deaths involved euthanasia.

Conclusions and Clinical Importance

Antibiotics were commonly prescribed in cats for treatment of UO despite minimal evidence in the clinical records of bacterial cystitis. Repeat catheterization was common and case fatality rate during a UO episode was high. Repeat catheterization within 48 hours of elective removal of a urethral catheter was less common in cats that had previously had indwelling catheters. The majority of cats requiring repeat catheterization survived until the end of the study.

Acute-phase proteins in cats with obstructive feline lower urinary tract disease

BACKGROUND

Feline obstructive disease of the lower urinary tract (FLUTD) is a common pathologic condition of cats. It can be related to sterile inflammation, which leads to acute impairment of renal function and the accumulation of electrolytes and acid-base imbalance. Acute-phase proteins (APPs) are biomarkers of tissue damage from inflammation that assist in monitoring treatment and prognosis.

OBJECTIVE

Monitoring the inflammatory processes of obstructive feline lower urinary tract disease through the determination of plasma fibrinogen concentrations and serum concentrations of the acute-phase proteins, serum amyloid A (SAA), alpha-1-acid glycoprotein (AGP), and albumin.

METHODOLOGY

Twenty-five male cats were included in this study. They were divided into two experimental groups: a control group (CG) and an obstruction group (OG). There were 8 healthy cats in the CG group and 17 cats with obstructive FLUTD in the OG group. APP measurements were conducted using ELISA kits. Samples were collected for APP analyses, serum biochemical assays, urinalyses, and urine protein: creatinine ratio calculations at diagnosis, before urethral clearance (H0), and 12 (H12), 24 (H24), and 48 (H48) hours after urethral clearance from cats in the OG group. Samples were collected once from cats in the CG group cats.

RESULTS

At H0, we found positive correlations of SAA, AGP, and fibrinogen with urea and creatinine, and negative correlations of albumin with hematuria, SAA, and potassium. At H48, we found positive correlations between SAA and AGP, AGP and urea, fibrinogen and urea, fibrinogen and creatinine, fibrinogen and AGP, and fibrinogen and SAA. In addition, a negative correlation of albumin with urea and creatinine was observed.

CONCLUSIONS

Serum amyloid A, AGP, fibrinogen, and albumin could be used as biomarkers of inflammatory processes in cats with obstructive FLUTD.

Feline Idiopathic Cystitis: Pathogenesis, Histopathology and Comparative Potential

Bladder pain syndrome (BPS) is a debilitating disease in humans, particularly women, with patients experiencing chronic, intractable, lower urinary and pelvic pain. Although rodent models have been used, feline idiopathic cystitis (FIC) is a naturally occurring bladder disease of cats that is frequently considered to be the preferred model for BPS. Histologically, FIC is most similar to the non-Hunner BPS subtype. Histology is unnecessary for the clinical diagnosis of FIC but is of great value in elucidating the pathogenesis of this disease so that prevention and therapeutic interventions can be optimized. Further study of the histological features of FIC and BPS is required to determine the significance of Von Brunn's nests, which are invaginations of hyperplastic urothelium that have been associated with irritative bladder stimuli in animals and have been observed in FIC. We review the possible pathogenesis, histopathological similarities and differences between FIC and BPS, and highlight the potential of FIC as a model of BPS.

Case Report: Application and Limitations of a Plant-Based Diet Formulated for a Cat With Feline Lower Urinary Tract Disease

A 2-year-old male castrated domestic shorthair cat was presented for recommendations for dietary management of chronic FLUTD using a strictly plant-based diet as per the stipulations of the cat's owner. The cat had a history of urethral obstruction of unknown etiology, persistent marked struvite crystalluria, and persistent inappropriate elimination. Commercial plant-based products meeting the nutritional recommendations for maintenance of adult cats with the lowest concentration of struvite precursors were identified, but the cat would not eat them. At the request of the client, a homemade plant-based diet was formulated with the intention of increasing water intake and promoting acidic, dilute urine. Urine concentration was able to be decreased somewhat and struvite crystalluria resolved, but the urine remained more alkaline than intended. The cat clinically improved and no further FLUTD episodes were reported by the client.

Effect of prazosin on feline recurrent urethral obstruction

OBJECTIVES

The aim of this study was to determine if male cats treated with 7 days of prazosin following relief of urethral obstruction (UO) experienced decreased rates of recurrent urethral obstruction (rUO) within 30 days vs those treated with 7 days of placebo.

METHODS

All castrated male cats presenting for the first time with UO from May 2014 to August 2017 were eligible for enrollment. Exclusion criteria included the administration of medications or passage of a urinary catheter prior to referral, the presence of heart disease or hypertension requiring medication, prior treatment with glucocorticoids, non-steroidal anti-inflammatory medications, prazosin or phenoxybenzamine, or radiographic identification of cystoliths. Cats were treated with standardized anesthetic and analgesic protocols, standardized indwelling urinary catheter management, and were hospitalized for care. A random numbers table was generated prior to study initiation and cats were randomized to receive either prazosin (0.5 mg PO q12h for 7 days) or placebo in a blinded fashion. A 30-day follow-up with owners via telephone was performed to identify the rate of rUO. Cats that did not receive the full course of study medication were removed from the analysis. The study was unblinded at the end of data collection.

RESULTS

Eighty cats were enrolled and 65 cats completed the study; 12 were excluded because they did not receive the study medication. Sixteen of 65 cats experienced rUO (25%). Of the 16 cats experiencing rUO, five received placebo (n = 5/28 [18%]) and 11 received prazosin (n = 11/37 [30%]). Ten of the cats that experienced rUO reblocked while still hospitalized. There was no significant difference in frequency of rUO in cats treated with prazosin vs placebo (P = 0.27).

CONCLUSIONS AND RELEVANCE

Prazosin administered at 0.5 mg PO q12h did not decrease the rate of rUO in this population of obstructed male cats vs placebo. These results further support evidence suggesting that prazosin may not be beneficial in prevention of feline rUO.

Retrospective interview-based long-term follow-up study of cats diagnosed with idiopathic cystitis in 2003-2009

OBJECTIVES

The aim of this study was to register long-term recurrence rates and mortality rates in cats diagnosed with feline idiopathic cystitis (FIC), with an observation period until death or a minimum of 10 years.

METHODS

Data regarding recurrence of signs of feline lower urinary tract disease (FLUTD) and FLUTD-related mortality in cats diagnosed with FIC between 2003 and 2009 were obtained through structured telephone interviews with the cat owners from December 2018 until February 2019. The interviews were based on a standardised questionnaire covering whether the cat was still alive or not, whether death/euthanasia were due to FLUTD and whether the cat had experienced recurrent episodes of clinical signs of FLUTD. If recurrences had occurred, exact numbers or estimates of 1-3, 4-6 or >6 recurrences were recorded.

RESULTS

The owners of 50/105 FIC cats included in a previous study (48%) were available for inclusion in the present study. At the time of the interview, only 6/50 cats (12%) were still alive. The FLUTD-related mortality rate was 20% (n = 10/50). Twenty-three cats (46%) had no recurrences, three cats (6%) were euthanased shortly after diagnosis, nine cats (18%) had 1-3 recurrences, three cats (6%) had 4-6 recurrences and six cats (12%) had >6 recurrences. For the remaining six cats, the number of recurrences was uncertain.

CONCLUSIONS AND RELEVANCE

The long-term prognosis for cats diagnosed with FIC may, based on the results from the present study, be regarded as fairly good, as approximately 70% of the cats either recovered without additional episodes, experienced only a few recurrences, are still alive after a minimum of 10 years since inclusion in the study, or were euthanased for reasons unrelated to FLUTD.

Evaluation of urethral orifice cross-section dimensions following perineal urethrostomy in male cats

OBJECTIVES

The aims of this study were: (1) To evaluate the urethral orifice cross-section size immediately and 12 days post-operatively following a perineal urethrostomy procedure. (2) To assess the correlation between the cross-section size and stricture formation during a 6-month period following the perineal urethrostomy.

ANIMALS

Twenty-four male cats with feline lower urinary tract disease that failed to respond to medical treatment and underwent perineal urethrostomy.

MATERIALS AND METHODS

The urethral orifice cross-section size was estimated by the largest size of the urinary catheter that was possible to insert facilely through the urethrostomy site. The urethral orifice cross-section size was measured in three different times: Pre-operative (LUCpr), immediately post-operative (LUCi) and 12 days post-operative (LUCp). Urinary obstruction recurrence and urethrostomy site stricture formation were documented for 6 months after the surgical procedure. The probabilities for obstruction recurrence in cases of LUCi ≤ 8Fr and LUCi > 8Fr were calculated.

RESULTS

Urinary obstruction and urethrostomy site stricture occurred in 5 of 24 (~20%) of the operated cats at an average of 92 ± 25 days post-perineal urethrostomy. LUCi ranged from 6 to 10 (median 10) Fr and the LUCp ranged from 4 to 10 (median 8) Fr. There was a significant decrease of 0.15 ± 0.09 mm² of the urethral orifice cross-section area 12 days post-operative compared to the measurements taken immediately post-operative. The probabilities for post-operative urinary obstruction of the LUCi ≤ 8Fr cases (intra-operative urethral orifice cross-section area equal or larger than 5.5 mm² ) and in the LUCi > 8Fr cases were 44 and 6%, respectively. Recurrence of obstruction was documented in all cases (three cats) in which LUCi was 6Fr.

CONCLUSION AND CLINICAL SIGNIFICANCE

The largest size of the urinary catheter that is possible to insert during surgery is a simple method to evaluate urethrostomy cross-section size. Contraction of the urethral orifice diameter is expected during the wound healing phase. Post-operative urinary obstruction is more likely in cases where LUCi < 8Fr.

A prospective randomized, double-blinded clinical study evaluating the efficacy and safety of bupivacaine versus morphine-bupivacaine in caudal epidurals in cats with urethral obstruction

OBJECTIVE

To investigate the efficacy and safety of the caudal epidural technique in cats with urethral obstruction (UO).

DESIGN

Prospective, double-blinded, randomized, sham-controlled study.

ANIMALS

Eighty-eight male cats with UO.

INTERVENTIONS

Thirty cats randomized to bupivacaine epidural (BUP), 28 cats to bupivacaine-morphine epidural (BUP/MOR), and 30 cats to sham epidural (SHAM).

MEASUREMENTS AND MAIN RESULTS

Time to perform the epidural and efficacy of the epidural was assessed by evaluation of tail and perineal responses. The amount of propofol for urinary catheterization and time to administration of rescue analgesia (buprenorphine) was recorded. Cats were monitored for epidural complications. The median time to perform the epidural was 2 min (range, 0.2-13 min and range, 0.5-13 min), with an epidural success rate of 70%. The median amount of propofol administered for urinary catheterization was significantly less in the BUP (2.1 mg/kg; range, 0-7.5 mg/kg) and MOR/BUP cats (1.85 mg/kg; range, 0-8.6 mg/kg) as compared to SHAM cats (4 mg/kg; range, 0-12.7 mg/kg) (P = 0.006, P = 0.0008, respectively). The median time to administration of rescue analgesia was also significantly longer in the BUP (10 h; range, 2-32 h) and MOR/BUP cats (10 h; range, 4-45 h) as compared to SHAM cats (4 h; range, 2-36 h) (P = 0.0026, P = 0.0004, respectively). There were no recognized complications related to the epidural.

CONCLUSION

Caudal epidural appears to be safe, may reduce the amount of IV anesthesia needed to facilitate urinary catheterization, and can be used to provide long-term analgesia in the hospital.

Retrospective evaluation of urinary indwelling catheter type in cats with urethral obstruction (January 2014 to December 2014): 91 cases

OBJECTIVE

To investigate the influence of urinary catheter type on recurrence rate (rUO) in cats with urethral obstruction.

DESIGN

Retrospective study.

SETTING

Two private referral hospitals.

ANIMALS

Ninety-one cats diagnosed with urethral obstruction treated with a 3.5-Fr Argyle (AR) or 3.5-Fr red rubber (RR) indwelling catheter presenting in 2014.

MEASUREMENTS AND MAIN RESULTS

One hundred sixty-six cats were identified using diagnostic code search with 91 cats meeting inclusion criteria. All were treated with IV fluids, buprenorphine, prazosin, and an indwelling urethral catheter with a closed collection system. Catheter groups did not differ statistically in baseline characteristics, medication treatment, or catheterization time. Follow-up was available for 91 cats at 24 hours, 86 cats at 7 days, and 84 cats at 30 days. There was no statistical difference in rUO between cats with different catheter types at any time in this retrospective study.

CONCLUSIONS

No difference in rUO was found in cats treated for urethral obstruction with a 3.5-Fr AR or RR catheter, however, due to the retrospective nature of this study the inability to detect a difference may be due to the small sample size of this study. Recurrent urethral obstruction in this study at 30 days was 11%.

Postmortem urinary tract changes in cats with urethral obstruction

OBJECTIVE

To report the gross and histopathological postmortem findings of the urinary tract and compare them to clinical severity of disease in cats with urethral obstruction (UO).

DESIGN

Retrospective, observational, descriptive study.

SETTING

University teaching hospital.

ANIMALS

Fourteen cats from 2000 to 2014 with UO that had a complete postmortem examination.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Bladder lesions were moderate-severe in 10 of 14 (71%) and mild in 4 of 14 (29%) cats. Bladder lesions were diffuse in 8 of 14 (57%), multifocal in 3 of 14 (21%), and focal in 3 of 14 (21%) cats. Lymphocytic cystitis was noted in 11 of 14 cats (78%), and neutrophilic cystitis was noted in 10 of 14 (71%) bladders. Urethral lesions were moderate-severe in 4 of 14 (29%), mild in 4 of 14 (29%), and no urethral lesions were identified in 6 of 14 (43%) cats. Ureteral lesions were mild in 1 of 14 (7%), and no ureteral lesions were identified in 13 of 14 (93%) cats. There were moderate-severe histopathological renal lesions in 5 of 14 cats (36%), mild renal lesions in 6 of 14 (43%), and no renal lesions were identified in 3 of 14 cats (21%). Renal lesions were multifocal in 10 of 14 (71%) and regional in 1 of 14 cats (7%). In the kidneys, the most common inflammatory infiltrate was lymphoplasmacytic. The severity of urethral lesions was not associated with the severity of bladder lesions (P = 1.0). Hyperkalemia paralleled the severity of bladder (P = 0.02) and renal lesions (P = 0.04). An association between the severity of bladder lesions and degree of azotemia could not be determined due to small sample size and removal of the most azotemic cats.

CONCLUSIONS

Substantial renal and urinary bladder inflammatory lesions were found in cats with UO. The severity of these findings paralleled the severity of blood potassium concentrations.

Welfare of cats 5-29 months after perineal urethrostomy: 74 cases (2015-2017)

OBJECTIVES

The objective of this study was to evaluate the long-term quality of life in cats following perineal urethrostomy.

METHODS

This study comprised a retrospective case series of 74 cats with urinary obstructions that received perineal urethrostomies at the American Society for the Prevention of Cruelty to Animals (ASPCA) Animal Hospital between September 2015 and July 2017. Medical records were reviewed for information on the number of obstructions prior to surgery, urinary tract problems at the time of surgery and other potential factors influencing long-term welfare. Owners were surveyed by telephone and text 5-29 months after their cat's surgery. Responses were compiled and analyzed to determine owner perception of welfare postsurgery, and to identify patterns in medical history and welfare outcomes.

RESULTS

In total, 105 cat owners were eligible for the survey; 74 responded. Altogether, 100% of responding individuals reported at least the same quality of life postsurgery compared with the cat's quality of life before demonstrating urinary problems (48% reported better). On a quality-of-life scale of 1-10 (10 = excellent), 100% of responding cat owners reported at least 7; 75% reported 10.

CONCLUSIONS AND RELEVANCE

Quality-of-life outcomes for cats 5-29 months after receiving perineal urethrostomy surgery were reported to be very good. Given this finding, and that perineal urethrostomy surgery should mitigate future blockages, we suggest considering perineal urethrostomy surgery as a standard tool to manage urinary obstructions in cats. The needs of the specific client and patient, including risks, costs and welfare of the cats, should drive the options for management of urinary obstructions in male cats.

A prospective randomized study of efficacy of 2 treatment protocols in preventing recurrence of clinical signs in 51 male cats with obstructive idiopathic cystitis

Background

Urethral obstruction (UO) is a common complication of feline idiopathic cystitis (FIC). Robust treatment recommendations to prevent its recurrence are scarce.

Objectives

To evaluate meloxicam treatment for prevention of clinical recrudescence in male cats with obstructive FIC.

Animals

Fifty‐one client‐owned cats.

Methods

Prospective, randomized clinical trial. Every male cat with FIC‐associated UO was deemed eligible for the study and was recruited during hospitalization. After discharge, cats were treated with phenoxybenzamine and alprazolam for 2 weeks, with (24 cats) or without (27 cats) low‐dose meloxicam (0.025 mg/kg/day PO) and monitored for 6 months.

Results

Cumulative number (%) of cats with recurrent UO at 10 days, 1‐, 2‐, and 6‐months after discharge was 1 (2%), 2 (4%), 4 (8%), and 8 (16%), respectively. Overall, 12 (24%) cats experienced signs of recurrent FIC within 6 months, with (8 cats) or without (4 cats) concurrent UO. No difference in the cumulative incidence of UO within 6 months was detected with addition of meloxicam (odds ratio [95% confidence interval], 0.63 [0.13‐2.97]; P = .70). All cats were alive at 6 months.

Conclusions and Clinical Importance

No clinical benefit was detected with the addition of low‐dose meloxicam to phenoxybenzamine and alprazolam treatment for 2 weeks after discharge. Nevertheless, this study was underpowered to identify potential differences, and its findings must be corroborated in larger studies.

Recurrence rate and long-term course of cats with feline lower urinary tract disease

OBJECTIVES

Feline lower urinary tract disease (FLUTD) causes clinical signs such as stranguria, pollakiuria, haematuria, vocalisation and periuria, and is often associated with recurring episodes. The primary objective of this study was to survey the long-term course of cats presenting with FLUTD in terms of recurrence rate and mortality.

METHODS

Data from cats that were presented with lower urinary tract signs from 2010 to 2013 were collected by telephone interview with cat owners, using a questionnaire. The observation period ranged from the first presentation due to FLUTD to the telephone interview or the cat's death. Data on diagnoses, recurrence of clinical signs and disease-free intervals, as well as implementation and impact of prophylactic measures (PMs), were collected and compared between groups with different aetiologies.

RESULTS

The study included 101 cats. Fifty-two cats were diagnosed with feline idiopathic cystitis, 21 with urolithiasis and 13 with bacterial urinary tract infection; 15 had no definitive diagnosis. Of the 86 cats with a known diagnosis, the recurrence rate was 58.1%, with no significant difference between groups. Twenty-one cats had one relapse, 12 had two relapses, 10 had three and seven had four to eight relapses within a median observation period of 38 months (range 0.5-138 months). Fourteen cats suffered from different causes of FLUTD at different episodes. Mortality due to FLUTD among all 101 cats was 5.0%. The recurrence rate in cats with urolithiasis receiving at least two PMs was significantly lower than the recurrence rate in those without PMs (P = 0.029).

CONCLUSIONS AND RELEVANCE

More than half of the cats with FLUTD presented with two or more recurrent episodes irrespective of the identified aetiology. Cats should be thoroughly investigated at each presentation as it cannot be presumed that the cause of FLUTD is the same at different episodes. The mortality due to FLUTD is lower than previously reported.

Incidence of bacteriuria at presentation and resulting from urinary catheterization in feline urethral obstruction

OBJECTIVE

To determine the incidence of bacteriuria at the time of presentation and as a result of indwelling urethral catheterization in naturally occurring feline urethral obstruction (UO).

DESIGN

Prospective observational study.

SETTING

University teaching hospital.

ANIMALS

A population of 34 male cats with UO admitted for standard medical care.

INTERVENTIONS

A presenting urine sample was obtained by cystocentesis (precatheterization). After catheterization (performed under strict aseptic technique), a urine sample was obtained through the urinary catheter every 24 hours, as well as just prior to catheter removal. Urine was applied to culture media within 30 minutes of collection or refrigerated immediately at 4°C for subsequent culture the following morning. Samples positive for growth (defined as > 10⁴ colony forming units/mL) had bacterial identification and susceptibility testing performed.

MEASUREMENTS AND MAIN RESULTS

All 34 cats enrolled had initial culture performed. Of these, 1 patient died and 2 were euthanized within 24 hours and therefore subsequent cultures were obtained. The remaining 31 cats had median catheterization time of 42 hours (range 20-110 hours). No urine cultures yielded growth at presentation (0/34). A total of 4 of 31 patients (13%) subsequently had bacterial cultures that yielded growth. In these cases, all yielded growth by the 24-hour time point, and all had the same organism identified on subsequent cultures. Identified bacteria included Streptococcus spp. (3) and Pasteurella spp. (1).

CONCLUSIONS

The male cats with UO in this study did not have bacteriuria at the time of presentation. The overall incidence of acquired bacteriuria was found to be 13% and could represent a transient bacterial population or true bacterial urinary tract infection. Based on these findings, empirical administration of antibiotics is not warranted in male cats with UO.

Evaluation of postoperative complication rates in cats undergoing perineal urethrostomy performed in dorsal recumbency

CASE SERIES SUMMARY

Medical records were reviewed for cats that underwent a perineal urethrostomy performed in dorsal recumbency for the treatment of urethral obstruction. Information, including signalment, reason for presentation, number of previous obstructions, surgery time, and perioperative and postoperative complications, were collected through a review of medical records and owner follow-up. The objective was to evaluate short- and long-term complications in cats that underwent perineal urethrostomy performed in dorsal recumbency for treatment of urethral obstruction.

RELEVANCE AND NOVEL INFORMATION

No major or life-threatening complications, such as urethral stricture, re-obstruction, euthanasia due to lower urinary signs or chronic urinary tract infection, were reported. Short-term complications were limited to dysuria in 2/12 (16.7%) cats. Long-term follow-up was available for nine cats. The most common long-term complication seen in this population of cats was a single recurrence of urinary tract infection in 3/9 (33.3%) cats that resolved after a short course of empirical antibiotic therapy. Performing perineal urethrostomy in dorsal recumbency is safe and may have advantages to ventral recumbency due to improved visualization, allowing for more efficient dissection and improved accuracy in tissue apposition during closure. We believe this has been a major contributor to our reported reduced major postoperative complication rate.

Associations between increased body condition score, bodyweight, age and breed with urethral obstruction in male castrated cats

Identifying potential risk factors for urethral obstruction in male cats may help in disease prevention. The aims of this study were to assess whether breed, pedigree status, age, bodyweight and body condition score (BCS) are risk factors for urethral obstruction in castrated male cats using a primary care population. Within this, a specific question was whether any increase in rate of urethral obstruction in male cats due to excess body condition is because of higher bodyweight. A retrospective hospital-based matched case-control study was performed using 195 cases of urethral obstruction in castrated male cats and 195 control consultations for cats presenting to a feline-only first opinion veterinary practice in Brisbane, Australia. The incidence rate of urethral obstruction did not vary significantly with bodyweight but increased with BCS (incidence rate ratio 1.6; 95% CI 1.2-2.1; P<0.001). The effect of BCS was not due to high BCS cats having higher bodyweights. The incidence was lower in Burmese cats compared to Domestic shorthair cats (incidence rate ratio 0.1; 95% CI 0.0-0.4; P=0.001), and higher in non-pedigree cats compared to pedigree cats (incidence rate ratio 2.8; 95% CI 1.7-4.6; P<0.001). Incidence rate ratios increased with age to 2 to 4years (the ages with highest incidences) then progressively declined with each additional year of age. Further research is needed to define why there is a positive association between BCS and rate of urethral obstruction. In the interim, clinicians should encourage owners of castrated male pet cats to ensure their cat's BCS is not high.

Routine Screening Examinations in Attendance of Cats With Obstructive Lower Urinary Tract Disease

This study evaluates the clinical findings obtained in routine screening examinations in cats with obstructive feline lower urinary tract disease at the time of service. Twenty-six cats with urethral obstruction were assessed by physical examination, blood pressure, electrocardiogram, and laboratory tests. Cats with signs of obstruction less than 36 hours before the service were in a state of alert, with body temperature and heart rate higher compared with cats in lethargy and stupor, obstructed up to 36 hours. The results revealed that 30.76% of the cats were hypertensive (>140mmHg). Arrhythmias were found in 15.38% of the cats with potassium >8.5mEqL. Creatinine, phosphorus, magnesium, potassium, and lactate concentrations were higher in cats obstructed more than 36 hours. All these data claim that a protocol of examinations should be established for obstructed cats, principally to stabilize the cat before the anesthesia for unobstruction.

Comparison of foods with differing nutritional profiles for long-term management of acute nonobstructive idiopathic cystitis in cats

OBJECTIVE

To evaluate the effect of nutrition on recurrent clinical signs of lower urinary tract (LUT) disease in cats with idiopathic cystitis.

DESIGN

Randomized, controlled, masked clinical trial.

ANIMALS

31 cats with acute nonobstructive idiopathic cystitis.

PROCEDURES

Cats were assigned to receive 1 of 2 foods (a cystitis prevention or control food) that differed in mineral (calcium, phosphorous, and magnesium), antioxidant, and fatty acid profiles. Owners documented LUT signs daily for up to 1 year. The primary endpoint was the number of recurrent episodes in which a cat had multiple (≥ 2 concurrent) LUT signs within a day (defined as multiple-sign day). Consecutive days in which a cat had multiple LUT signs were considered as a single episode.

RESULTS

4 cats fed prevention food and 2 cats fed control food were excluded from analysis because of noncompliance, gastrointestinal signs, food refusal, or owner voluntary withdrawal. The proportion of cats fed prevention food that had ≥ 1 recurrent episode of multiple-sign days (4/11) was not significantly lower than that of cats fed control food (9/14). However, cats fed prevention food had significantly lower mean incidence rates for recurrent episodes of multiple-sign days (0.7 episodes/1,000 cat-days) and episodes of hematuria (0.3 episodes/1,000 cat-days), dysuria (0.2 episodes/1,000 cat-days), and stranguria (0.2 episodes/1,000 cat-days) as single LUT signs, compared with cats fed control food (5.4, 3.4, 3.1, and 3.8 episodes/1,000 cat-days, respectively). Significantly fewer cats fed prevention food required analgesics (4/11), compared with cats fed control food (12/14).

CONCLUSIONS AND CLINICAL RELEVANCE

Foods with differing nutritional profiles appeared to impact mean incidence rates of recurrent feline idiopathic cystitis-associated signs.

Evaluation of meloxicam for the treatment of obstructive feline idiopathic cystitis

Objectives The aim of the study was to investigate the effect of the non-steroidal anti-inflammatory drug meloxicam on the clinical course of obstructive idiopathic cystitis in cats in a placebo-controlled clinical study. Methods Thirty-seven cats with obstructive idiopathic cystitis were enrolled. Cats received supportive treatment and an indwelling transurethral catheter for 48 h. On days 0 and 1, all cats received buprenorphine 0.01 mg/kg subcutaneously every 8 h. On day 1, cats were randomly assigned to the meloxicam (n = 18) or placebo group (n = 19) and received meloxicam (0.1 mg/kg on day 1, 0.05 mg/kg on days 2-5) or placebo orally for five consecutive days. Cats were monitored by repeated physical examinations and urinalysis, and with a 5 day questionnaire filled in by the owners after discharge and a telephone interview 3 months after presentation. Parameters for evaluation of treatment success were the occurrence of recurrent urethral obstruction, results of physical examinations and questionnaires. Results Recurrent urethral obstruction occurred in 4/18 cats (22%) in the meloxicam group and 5/19 cats (26%) in the placebo group ( P = 1.000). General demeanour and pain on abdominal palpation during hospitalisation improved significantly in both groups ( P <0.001). After discharge, with regard to general demeanour, food intake and voiding behaviour, there were no significant differences within or between groups at different time points. Conclusions and relevance Orally administered meloxicam for 5 days did not influence the incidence of recurrent urethral obstruction and the recovery from clinical signs in cats with obstructive feline idiopathic cystitis. The persistence of clinical signs in most of the cats 1 week after initial presentation indicates that symptomatic treatment for a longer period of time is warranted.

Severe anemia in cats with urethral obstruction: 17 cases (2002-2011)

OBJECTIVE

To characterize clinical parameters of cats with severe anemia due to suspected urinary bladder hemorrhage associated with urethral obstruction.

DESIGN

Retrospective case-control study.

SETTING

University teaching hospital.

ANIMALS

Seventeen cats with urethral obstruction and severe anemia (group "UO-A") that required transfusion were identified via medical record database search. Thirty cats with urethral obstruction and mild or no anemia (group "UO") were included as controls.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The median PCV of all cases at presentation was 28% (range, 9%-47%). Seven cats had PCV ≤20% at presentation, and all transfused cats had PCV ≤20% at the time of transfusion. Three cats did not receive a transfusion despite PCV ≤18%. Cats in the UO-A group had a significantly longer duration of clinical signs (P = 0.001), and were more likely to have a history of previous urethral obstruction (P = 0.011), have a heart murmur (P = 0.002), have a gallop rhythm (P = 0.005), and have lower blood pressure (P = 0.007) compared to those in the UO group. Additionally, UO-A cats had significantly lower pH, more negative base excess, higher BUN, and higher creatinine compared to UO cats. Duration of urinary catheterization was significantly (P = 0.016) longer in UO-A cats. All UO cats survived to discharge, whereas 4/17 (23.5%) UO-A cats were euthanized (P = 0.013).

CONCLUSIONS

A history of previous urethral obstruction and longer duration of clinical signs may be important risk factors for severe anemia in UO cats. Additionally, UO-A cats appeared to be more severely affected, as evidenced by lower blood pressure, more severe metabolic acidosis, higher BUN and creatinine, and worse outcome.

Efficacy of intravesical pentosan polysulfate sodium in cats with obstructive feline idiopathic cystitis

Objectives

Obstructive feline idiopathic cystitis is a common emergency in small animal practice. There is evidence for a defective glycosaminoglycan layer in the urinary bladder of affected cats. The aim of this study was to investigate the effect of intravesical pentosan polysulfate sodium (PPS) in cats with obstructive feline idiopathic cystitis in a randomised, placebo-controlled, blinded clinical study.

Methods

Thirty-five cats with obstructive feline idiopathic cystitis were enrolled into the study. On day 0, cats were randomised to receive either 30 mg PPS in saline (18 cats) or saline alone as placebo (17 cats) at the time of indwelling urinary catheter placement and then after 24 and 48 h. The catheter was clamped for 30 mins after administration before connecting it to a sterile urine collection system. The procedure was repeated after 24 and 48 h, and then the indwelling catheter was removed. Treatment success was assessed via the incidence of recurrent urethral obstruction, results of a scoring system for physical examination and daily urinalysis from day 0 to 5.

Results

Recurrent urethral obstruction occurred in 3/18 cats of the verum group and 3/17 of the placebo group ( P = 1.000). The verum group showed a significantly lower degree of microscopic haematuria between day 5 and day 0 ( P ⩽0.05). The placebo group showed a significantly lower degree of dipstick haematuria between day 5 and day 0 ( P ⩽0.05). There was no difference in the clinical score between the groups in the investigated time period.

Conclusions and relevance

Intravesical instillation of PPS three times within 48 h in the chosen dose had no influence on the incidence of recurrent urethral obstruction and clinical signs in cats with obstructive feline idiopathic cystitis.

ASSOCIATIONS BETWEEN ULTRASOUND AND CLINICAL FINDINGS IN 87 CATS WITH URETHRAL OBSTRUCTION

Urethral obstruction is a life-threatening form of feline lower urinary tract disease. Ultrasonographic risk factors for reobstruction have not been previously reported. Purposes of this retrospective cross-sectional study were to describe urinary tract ultrasound findings in cats following acute urethral obstruction and determine whether ultrasound findings were associated with reobstruction. Inclusion criteria were a physical examination and history consistent with urethral obstruction, an abdominal ultrasound including a full evaluation of the urinary system within 24 h of hospitalization, and no cystocentesis prior to ultrasound examination. Medical records for included cats were reviewed and presence of azotemia, hyperkalemia, positive urine culture, and duration of hospitalization were recorded. For medically treated cats with available outcome data, presence of reobstruction was also recorded. Ultrasound images were reviewed and urinary tract characteristics were recorded. A total of 87 cats met inclusion criteria. Common ultrasound findings for the bladder included echogenic urine sediment, bladder wall thickening, pericystic effusion, hyperechoic pericystic fat, and increased urinary echoes; and for the kidneys/ureters included pyelectasia, renomegaly, perirenal effusion, hyperechoic perirenal fat, and ureteral dilation. Six-month postdischarge outcomes were available for 61 medically treated cats and 21 of these cats had reobstruction. No findings were associated with an increased risk of reobstruction. Ultrasonographic perirenal effusion was associated with severe hyperkalemia (P = 0.009, relative risk 5.75, 95% confidence interval [1.54-21.51]). Findings supported the use of ultrasound as an adjunct for treatment planning in cats presented with urethral obstruction but not as a method for predicting risk of reobstruction.

Controversies in the management of feline urethral obstruction

OBJECTIVE

To discuss areas of differing opinion in the management of feline urethral obstruction and present current evidence to either support or refute common practices.

ETIOLOGY

Urethral obstruction may occur as a result from a functional obstruction (idiopathic obstruction) or a physical obstruction, such as mucous plugs or calculi within the urethra. Potential risk factors for obstruction in cats include predominantly indoor status, decreased water intake, and increased body weight.

DIAGNOSIS

The diagnosis is most commonly made based on history and initial physical exam-straining to urinate, vocalizing, signs of systemic illness, moderate to large firm bladder on abdominal palpation.

THERAPY

Treatment is based on available evidence. The type of IV isotonic crystalloid used does not seem to matter and rate should be determined by need for fluid resuscitation, and replacement of deficit and ongoing losses. Though controversial, cystocentesis appears to be safe and may offer some benefits in initial management. There is evidence to suggest a smaller urethral catheter (3.5 Fr) may be associated with decreased risk of reobstruction. Routine use of antimicrobial agents in hospital is not recommended; they should be dispensed based on culture performed at the time of catheter removal. Though commonly used, evidence in support of antispasmodics is limited and further prospective investigation is needed.

PROGNOSIS

Feline urethral obstruction is associated with 90-95% survival, with reported recurrence rates of 15-40%. Potential factors affecting recurrence include size or duration of indwelling urinary catheter, use of antispasmodic agents, patient age, and indoor-outdoor lifestyle; however, different studies offer conflicting results. Increased water intake and environmental modification do seem to decrease risk of recurrence.

Outcome of male cats managed for urethral obstruction with decompressive cystocentesis and urinary catheterization: 47 cats (2009-2012)

OBJECTIVE

To characterize the duration of urinary catheterization, length of hospitalization, complications and clinical outcome in cats with urethral obstruction managed with decompressive cystocentesis and subsequent urinary catheterization.

DESIGN

Retrospective, observational, descriptive study.

SETTING

University teaching hospital.

ANIMALS

Forty-seven client-owned male cats diagnosed with urethral obstruction.

MEASUREMENTS AND MAIN RESULTS

The medical records of 47 cats diagnosed with urethral obstruction were reviewed. Treatment of all cats included decompressive cystocentesis, placement of an indwelling urinary catheter and hospitalization for a minimum of 6 hours. Collected data included signalment, body weight, body condition score, owner-reported clinical signs, duration of clinical signs, vital signs, and venous blood gas or chemistry values. Mean duration of urinary catheterization was 27.9 hours, median length of hospitalization was 40 hours, and survival to discharge was 91%. Of 34 cats that had survey abdominal radiographs, 56% (19/34) had loss of peritoneal detail consistent with abdominal effusion. No cat was diagnosed with a ruptured bladder during hospitalization.

CONCLUSIONS

Decompressive cystocentesis, in cats with urethral obstruction, followed by placement of an indwelling urinary catheter, did not result in a diagnosis of bladder rupture in any cat. The source of and clinical significance of the reported abdominal effusion is not known. Survival to discharge, duration of catheterization, and length of hospitalization were similar to previously reported populations.

Correlation of gross urine color with diagnostic findings in male cats with naturally occurring urethral obstruction

Seventy-five male cats with urethral obstruction were prospectively enrolled to evaluate gross urine color at urinary catheter placement for correlation with diagnostic findings. Cats with darker red urine were more likely to be azotemic (serum creatinine concentration >2.0 mg/dl [177 µmol/l]), and urine color correlated well with serum creatinine and serum potassium concentrations. Darker urine color was negatively correlated with urine specific gravity. Urine color was not associated with the presence or absence of lower urinary tract stones on radiographs or ultrasound. Cats with darker red urine at the time of urinary catheter placement are likely to have more significant metabolic derangements and may require more aggressive supportive care.

Intravesical glycosaminoglycans for obstructive feline idiopathic cystitis: a pilot study

Feline idiopathic cystitis is a common condition, often resulting in repeated episodes of life-threatening urethral obstruction. Defective urinary bladder glycosaminoglycans have been implicated as a causal factor. In this report, a commercially available glycosaminoglycan product was infused into the urinary bladders of cats with urethral obstruction from idiopathic cystitis to study the effect on repeated obstruction. In this randomized, blind, placebo-controlled clinical trial, the therapeutic protocol was well tolerated with no adverse effects. Whereas no glycosaminoglycan-treated cats (n = 9) developed repeated urethral obstruction during the 7 day follow-up period, 3/7 placebo-treated cats developed repeated obstructions. Approaching statistical significance ( P = 0.06), these data suggest that further investigation of this new treatment option is warranted.

Management of urinary tract emergencies in small animals

This article focuses on some of the most commonly seen urinary tract emergencies in dogs and cats, with emphasis on basic pathophysiology, diagnosis, and emergency management of these cases.

Companion Animals Symposium: dietary management of feline lower urinary tract symptoms

Experimental and clinical investigations have confirmed the importance of dietary modifications in medical protocols designed to treat and prevent feline lower urinary tract signs (LUTS). The objective of this review is to discuss common medical conditions contributing to feline LUTS and to present currently used and potential preventative dietary modifications. Feline LUTS are a set of clinical conditions with similar symptoms related to inappropriate urine elimination due to a combination of genetics, stress and frustration reactions, environment, and medical condition or conditions, for example, idiopathic cystitis, urolithiasis, urethral obstruction, and urinary tract infection. The main goals of dietary modifications to prevent LUTS are 1) promote large dilute volumes of urine, 2) decrease the relative supersaturation of urine for specific stone types, and 3) promote healthy bacterial populations in the gastrointestinal and urogenital tracts. The impact of dietary composition, including dietary moisture, protein concentration and digestibility, mineral concentrations (i.e., Na, Cl, Ca, P, and Mg), inclusion of acidifiers and alkalinizing agents, inclusion of vitamin B6, eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and γ-linolenic acid, fiber concentration and characteristics, and oxalate degrading probiotics, on these outcomes is discussed, and dietary guidelines for cats are provided. Because of the complex interaction of diet composition, environment, and animal physiology, there is a need for clinical research linking current recommendations or dietary options for the treatment and prevention of LUTS with physiological outcomes (i.e., decreased relative supersaturation and LUTS recurrence). Additionally, for many recommendations (e.g., probiotic administration, EPA, DHA), extrapolation from other species was necessary. Research is needed in feline patients with LUTS on these dietary components.

Stones in cats and dogs: What can be learnt from them?

Objective

To review the clinical features of stone disease in dogs and cats for a non-veterinary audience.

Methods

Relevant peer-reviewed scientific reports were reviewed.

Results

Lower urinary tract stones are more common in dogs and cats than they are in humans. In addition to struvite stones, calcium oxalate, urate and cystine stones are all commonly found in the bladder and the urethra. The genetic basis for stone disease in some breeds of dog has been elucidated. The small size of cats creates technical challenges when managing ureterolithiasis.

Conclusions

Naturally occurring stone disease in companion animals is a valuable area for further study. The structure of the canine genome might facilitate the identification of novel disease loci in breeds of dog predisposed to stone formation.