Chronic Lower Urinary Tract Signs in Cats

Interstitial cystitis-an imbalance of risk and protective factors?

Interstitial cystitis (IC) presents as a chronic pain condition with variable combinations of symptoms depending on the species and individual patient. It is diagnosed by the presence of lower urinary tract signs and symptoms in combination with a variety of comorbid health problems, a history of life adversities, and the absence of other conditions that could cause the lower urinary tract signs. IC occurs naturally in humans and cats as a dimensional condition, with patients presenting with mild, moderate, and severe symptoms. Most patients appear to recover without specific treatment. A number of rodent models of IC have been used to study its causes and treatments. Unfortunately, current therapies generally fail to ameliorate IC symptoms long-term. The recent classification of IC as a chronic primary pain disorder calls for a rethinking of current clinical and research approaches to it. Beginning when a patient encounters a clinician, precipitating, perpetuating, and palliating risk factors can be addressed until a cause or reliably effective therapy is identified, and identifying predisposing and preventive factors can inform epidemiological studies and health promotion interventions. Predisposing, precipitating, and perpetuating risk factors, including environmental, psychological, and biological, increase the activity of the central threat response system (CTRS), which plays a clinically important role in IC symptoms. Studies in cats and rodent models have revealed that environmental enrichment (EE), in the absence of bladder-directed therapies, leads to amelioration of IC symptoms, implying a central role for the CTRS in symptom precipitation and perpetuation. Conceptually moving the source of IC pain to the brain as a motivational state rather than one resulting from peripheral nociceptive input offers both clinicians and researchers novel opportunities to improve care for patients with IC and for researchers to use more ecologically valid rodent models. It may even be that IC results from an excess of risk to protective factors, making this imbalance a targetable cause rather than a consequence of IC.

No viable bacterial communities reside in the urinary bladder of cats with feline idiopathic cystitis

Urinary microbial diversities have been reported in humans according to sex, age and clinical status, including painful bladder syndrome/interstitial cystitis (PBS/IC). To date, the role of the urinary microbiome in the pathogenesis of PBS/IC is debated. Feline idiopathic cystitis (FIC) is a chronic lower urinary tract disorder affecting cats with similarities to PBS/IC in women and represents an important problem in veterinary medicine as its aetiology is currently unknown. In this study, the presence of a bacterial community residing in the urinary bladder of cats with a diagnosis of FIC was investigated. Nineteen cats with clinical signs and history of FIC and without growing bacteria in standard urine culture were included and urine collected with ultrasound-guided cystocentesis. Bacterial community was investigated using a culture-dependent approach consisted of expanded quantitative urine culture techniques and a culture-independent approach consisted of 16S rRNA NGS. Several methodological practices were adopted to both avoid and detect any contamination or bias introduced by means of urine collection and processing which could be relevant due to the low microbial biomass environment of the bladder and urinary tract, including negative controls analysis. All the cats included showed no growing bacteria in the urine analysed. Although few reads were originated using 16S rRNA NGS, a comparable pattern was observed between urine samples and negative controls, and no taxa were confidently classified as non-contaminant. The results obtained suggest the absence of viable bacteria and of bacterial DNA of urinary origin in the urinary bladder of cats with FIC.

Uroprotective and pain-relieving effect of dietary supplementation with micronized palmitoyl-glucosamine and hesperidin in a chronic model of cyclophosphamide-induced cystitis

Introduction

Feline idiopathic cystitis is a common, chronic-relapsing disorder of the lower urinary tract. In addition to environmental modification/enrichment, long-term and safe treatment targeting specific pathophysiological changes may be of help. In this context, effective dietary interventions hold clinical promise. Palmitoyl-glucosamine (PGA) and hesperidin (HSP) are safe and authorized feed ingredients for animal nutrition under European regulations.

Methods

The current study aimed to investigate whether a 3:1 mixture of micronized PGA and HSP could represent a novel mechanism-oriented approach to chronic cystitis management. A newly validated rat model of cyclophosphamide (CYP)-induced chronic cystitis was used (40 mg/kg, three intraperitoneal injections every 3rd day). Animals were randomized to orally receive either vehicle or PGA-HSP at a low (72 + 24 mg/kg) or high (doubled) dose for 13 days, starting 3 days before the chronic CYP protocol, with mesna (2-mercaptoethane-sulfonate) being used as a reference drug.

Results

Higher PGA-HSP dose was effective at relieving chronic visceral pain, as measured by mechanical allodynia test (von Frey test). The severity of cystitis was also significantly improved, as shown by the reduced sonographic thickening of the bladder wall, as well as the decrease in edema, bleeding and bladder to body weight ratio compared to the vehicle treated group. A significant decrease of MPO activity, MDA level and fibrosis at Masson's trichrome staining was also observed in animals administered PGA-HSP in comparison to vehicle treated ones. The CYP-induced increase in bladder mRNA expression of pro-inflammatory cytokines was also significantly counteracted by the study mixture. Moreover, CYP-induced bladder mast cell accumulation and releasability were significantly decreased by PGA-HSP (even at the low dose), as determined by metachromatic staining, chymase and tryptase immunostaining as well as enzyme-linked immunosorbent assay for histamine and 5-hydoxytriptamine.

Discussion

PGA-HSP is able to block CYP-induced decrease of tight junction proteins, claudin-1 and occludin, thus preserving the urothelial bladder function. Finally, neuroinflammatory changes were investigated, showing that dietary supplementation with PGA-HSP prevented the activation of neurons and non-neuronal cells (i.e., microglia, astrocytes and mast cells) at the spinal level, and counteracted CYP-induced increase of spinal mRNA encoding for pro-inflammatory cytokines. Altogether, the present findings confirm the uroprotective and pain-relieving effect of PGA-HSP and pave the way to potential and relevant clinical applications of the study supplement in feline idiopathic cystitis.

Diagnostic effectiveness of stress biomarkers in cats with feline interstitial and bacterial cystitis

BACKGROUND

Although bacterial cystitis (BC) and feline interstitial cystitis (FIC) are categorized under feline lower urinary tract disease (FLUTD) due to their similar clinical manifestations, stress is an important factor for FIC. Therefore, the investigation of stress biomarkers might be important in the differentiation and elucidation of these conditions.

OBJECTIVES

We aimed to evaluate the diagnostic effectiveness of serum and urine cortisol, serotonin, and dopamine concentrations and their relationship with stress in cats with FIC and BC.

METHODS

Twelve healthy cats (Control group) and 24 cats with FLUTD were used. The cats with FLUTD were divided into FIC and BC groups.

RESULTS

Multimodal environmental modification (MEMO) scores were found to be higher in the FIC group than in the BC and Control groups (P < .001). Urine serotonin concentrations were higher in cats with FIC and BC compared with those in the Control group. Based on ROC analyses, the sensitivity, specificity, and accuracy of urine serotonin and dopamine were found to be statistically significant in being able to differentially diagnose cats in the FIC group vs the Control group. The sensitivity, specificity, and accuracy of serum dopamine were also found to be statistically significant for the differential diagnosis of FIC and BC.

CONCLUSIONS

High urine serotonin concentrations were found in cats with FLUTD compared with healthy controls and interpreted as the presence of stress not only in cats with FIC but also in cats with BC. Also, based on the ROC-based diagnostic performance evaluation of these stress biomarkers, urine serotonin, and dopamine concentrations can be used to diagnose FIC, and serum dopamine concentrations can be used to differentiate FIC and BC in cats.

Comparative evaluation of selected serum and urine biomarkers in cats with interstitial and bacterial cystitis

BACKGROUND

Although feline urine is increasingly submitted for bacterial culture and susceptibility testing in veterinary practice, bacterial cystitis (BC) is relatively uncommon compared with feline interstitial cystitis (FIC), which shares similar clinical manifestations. Therefore, an investigation of certain urothelial (glycosaminoglycan [GAG], tissue inhibition metalloproteinase-2 [TIMP-2]), cytokine (interleukin 12 [IL-12]), and neurotrophic factor (nerve growth factor [NGF]) markers may aid diagnosis.

OBJECTIVES

We aimed to evaluate the diagnostic effectiveness of selected serum/urine biomarkers in the diagnosis of cats with FIC and BC.

METHODS

Twelve healthy cats (Control group) and 24 cats with feline lower urinary tract disease (FLUTD) were used, and the cats with FLUTD were divided into FIC and BC groups.

RESULTS

When comparing the three groups, serum GAG, IL-12, NGF, and TIMP-2 concentrations were highest in the FIC group; urine GAG, IL-12, NGF, and TIMP-2 concentrations were higher in the FIC and BC groups than those in the Control group. Serum NGF concentrations were higher in the FIC group than in all other groups. Also, serum GAG, IL-12, NGF, and TIMP-2 concentrations were found to be effective in the differential diagnosis of FIC vs BC.

CONCLUSIONS

We showed that serum NGF is a candidate biomarker that could be used in the diagnosis and differentiation of FIC. Urine GAG, IL-12, NGF, and TIMP-2 concentrations might be helpful in determining urinary bladder inflammation and/or damage in cats with FIC and BC. ROC analyses revealed that serum and urine biomarkers were effective for diagnosing FIC and that serum biomarkers rather than urine biomarkers were effective for the differential diagnosis of FIC and feline BC.

The Unmet Needs for Studying Chronic Pelvic/Visceral Pain Using Animal Models

The different definitions of chronic pelvic/visceral pain used by international societies have changed over the years. These differences have a great impact on the way researchers study chronic pelvic/visceral pain. Recently, the role of systemic changes, including the role of the central nervous system, in the perpetuation and chronification of pelvic/visceral pain has gained weight. Consequently, researchers are using animal models that resemble those systemic changes rather than using models that are organ- or tissue-specific. In this review, we discuss the advantages and disadvantages of using bladder-centric and systemic models, enumerating some of the central nervous system changes and pain-related behaviors occurring in each model. We also present some drawbacks when using animal models and pain-related behavior tests and raise questions about possible, yet to be demonstrated, investigator-related bias. We also suggest new approaches to study chronic pelvic/visceral pain by refining existing animal models or using new ones.

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.

Evaluating feline lower urinary tract disease: Doppler ultrasound of the kidneys

OBJECTIVES

Ultrasonography is used in the evaluation of urinary disorders, and the resistivity index (RI) and pulsatility index (PI) have been successfully used to detect early hemodynamic changes in the course of kidney diseases in humans and dogs. The aim of this study was to investigate RI and PI in cats with feline lower urinary tract disease (FLUTD).

METHODS

Twenty-nine client-owned cats were selected and divided into a control group (CG; n = 10), a group of animals with obstructive FLUTD (OG; n = 11) and non-obstructive FLUTD (nOG; n = 8). Clinical, laboratory and ultrasound evaluations were performed in all cats.

RESULTS

RI and PI values for cats in the CG were below the upper limit of normal suggested in other studies, while cats with FLUTD showed significantly higher values in the assessment of RI (P = 0.027 and P = 0.034, respectively) and PI (P = 0.044 and P = 0.048, respectively) of the right and left kidneys.

CONCLUSIONS AND RELEVANCE

Alteration in renal blood flow was observed in cats with lower urinary tract disorders, even in the nOG group. To the best of our knowledge, this is the first report of renal blood flow changes related to non-obstructive FLUTD.

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.

Dysbiosis of the Urinary Bladder Microbiome in Cats with Chronic Kidney Disease

Although feline urinary tract diseases cause high morbidity and mortality rates, and subclinical bacteriuria is not uncommon, the feline urinary microbiome has not been characterized. We conducted a case-control study to identify the feline urinary bladder microbiome and assess its association with chronic kidney disease (CKD), feline idiopathic cystitis (FIC), and positive urine cultures (PUCs). Of 108 feline urine samples subjected to 16S rRNA gene sequencing, 48 (44.4%) samples reached the 500-sequence rarefaction threshold and were selected for further analysis, suggesting that the feline bladder microbiome is typically sparse. Selected samples included 17 CKD, 9 FIC, 8 PUC cases and 14 controls. Among these, 19 phyla, 145 families, and 218 genera were identified. Proteobacteria were the most abundant, followed by Firmicutes. Notably, four major urotypes were identified, including two urotypes predominated by Escherichia-Shigella or Enterococcus and two others characterized by relatively high alpha diversity, Diverse 1 and Diverse 2. Urotype was associated with disease status (P value of 0.040), with the Escherichia-Shigella-predominant urotype being present in 53% of CKD cases and in all of the Escherichia coli PUC cases. Reflecting these patterns, the overall microbial composition of CKD cases was more similar to that of E. coli PUC cases than to that of controls (P value of <0.001). Finally, PUC cases had microbial compositions distinct from those of controls as well as CKD and FIC cases, with significantly lower Shannon diversity and Faith’s phylogenetic diversity values.

IMPORTANCE Despite the clinical importance of urinary diseases in cats, the presence of resident urine microbes has not been demonstrated in cats, and the role of these microbes as a community in urinary health remains unknown. Here, we have shown that cats with and without urinary tract disease harbor unique microbial communities in their urine. We found no evidence to suggest that the bladder microbiome is implicated in the pathogenesis of feline idiopathic cystitis, a disease similar to bladder pain syndrome/interstitial cystitis in humans. However, cats with chronic kidney disease had dysbiosis of their bladder microbiome, which was predominated by Escherichia-Shigella and had a community structure similar to that of cats with Escherichia coli cystitis. These findings suggest that chronic kidney disease alters the bladder environment to favor Escherichia-Shigella colonization, potentially increasing the risk of overt clinical infection.

Antimicrobial susceptibility of bacterial isolates from urinary tract infections in companion animals in Spain

BACKGROUND

The increasing emergence of multidrug-resistant bacteria, causing urinary tract infections (UTI) in dogs and cats, represents a great therapeutic challenge and a public health concern.

METHODS

Laboratory records of 4943 urinary microbiological diagnosis results and antimicrobial resistance profiles of suspected UTI cases in dogs and cats were analysed from 2016 to 2018 in Spain.

RESULTS

This study showed a higher percentage of positive microbiological diagnoses in dogs (42%, 1368/3270) than in cats (27%, 457/1673). Although Escherichia coli was the most frequently isolated bacterium, the frequency of antimicrobial susceptibility of E. coli isolates was lower compared to other bacterial species like Enterococcus spp., Staphylococcus spp., Klebsiella pneumoniae, Pseudomonas aeruginosa, Enterobacter (E. cloacae), and Proteus mirabilis. The antimicrobial susceptibility testing of Gram-positive cocci showed higher levels of resistance in cats to common beta-lactams used for the treatment of complicated UTIs, as well as to fluoroquinolones, aminoglycosides, and carbapenems. Moreover, enterobacteria (E. coli, K. pneumoniae, and P. mirabilis) from cats presented high resistance frequencies to beta-lactams, including third- and fourth-generation cephalosporins and fluoroquinolones.

CONCLUSION

This study updates data on the current antimicrobial resistance in UTI bacteria from companion animals in Spain, which may help to guide clinicians for the appropriate use of antimicrobials.

A case of behavioral changes in a castrated male cat due to a functional adrenocortical adenoma producing testosterone and androstenedione

Case summary

This case report describes a 9-year-old neutered male cat with a functional adrenal tumor showing aggression toward other cats in the household, excessive meowing and urine spraying. The diagnosis was made based on the clinical signs, an enlarged right adrenal gland on ultrasound, penile spines and elevated sex hormones on an adrenocorticotropic hormone stimulation test. The cat was submitted to celiotomy and adrenalectomy. Histopathological examination confirmed the adrenocortical adenoma. Three months after surgery the penile spines disappeared and urine spraying, as well as excessive meowing, had greatly decreased; however, aggressive behavior took much longer to stop and required behavior therapy.

Relevance and novel information

Functional adrenal tumors producing only sex hormones and behavioral changes are uncommon. The cat reported herein started showing behavioral changes before spines appeared on the penis, and structural alterations in the adrenal gland at the abdominal ultrasonography were detected. Considering all the possible implications resulting from severe behavior problems such as cat-cat aggression, from a permanent separation of the cats to relinquishment, a detailed investigation of underlying medical mechanisms in these animals is crucial from the start. Examinations may need to be repeated later in the course.

Postoperative outcomes of 12 cats with ureteral obstruction treated with ureteroneocystostomy

OBJECTIVE

To report complications and long-term outcomes of cats with benign ureteral obstruction treated with ureteroneocystostomy and to determine the effects of double pigtail catheter (DPT) placement on postoperative outcomes.

STUDY DESIGN

Retrospective study.

ANIMALS

Twelve client-owned cats with ureteral urolithiasis treated with ureteroneocystostomy.

METHODS

Records were reviewed for signalment, location of the obstruction, diagnostic tests, surgical technique, perioperative complications, long-term measurements of kidney function, and survival. Cats were divided into two groups; in one group, a DPT was placed at the time of ureteroneocystostomy, and, in the other group, a DPT was not placed at the time of ureteroneocystostomy (NDPT).

RESULTS

A DPT was placed in six of 12 cats. The NDPT group included four cats with temporary catheters and two cats with no catheter. Median creatinine concentration decreased from 10.4 mg/dL (range, 1.6-20.3) to 2.2 mg/dL (range, 1.1-3.6) at the time of discharge (P = .015) in all cats. Two cats in the NDPT group required revision surgery for uroabdomen. Eleven cats were discharged from the hospital. Long-term complications (hematuria, pollakiuria, urinary tract infections) were more common in the DPT group (P = .047). Seven cats were alive a median of 329 days (range, 8-1772) after surgery. Median creatinine concentration was 2.0 mg/dL (range, 0.6-6.4) at a median of 157 days (range, 43-1772) after surgery.

CONCLUSION

Ureteroneocystostomy resulted in acceptable long-term outcomes in 11 of 12 cats. The placement of a DPT did not influence the long-term outcome in this small population.

CLINICAL SIGNIFICANCE

Ureteroneocystostomy with or without intraoperative placement of a DPT should be considered to relieve benign ureteral obstructions in cats.

Feline Neuropathic Pain

Neuropathic pain represents the extreme in maladaptive pain processing. In itself, it is a disease in which pain has become exaggerated in some combination of scope, severity, character, field, duration, and spontaneity. It is almost certainly an underappreciated, underdiagnosed cause of possible significant patient morbidity in cats. This article explores the basic mechanisms, recognition, known and suspect syndromes, and prospective treatment of feline maladaptive and neuropathic pain.

Evaluation of Severity and Factors Contributing to Foot Lesions in Endangered Ozark Hellbenders, Cryptobranchus alleganiensis bishopi

Arkansas populations of Ozark Hellbenders, Cryptobranchus alleganiensis bishopi have declined precipitously over the past few decades and are now limited to a single river. Biologists have also observed an increase of distal limb lesions with unidentified etiology and unknown role in morbidity and mortality of the species in this location. We documented lesions and collected associated individual size class data and pathogen samples in Ozark Hellbenders of Arkansas (n = 73) from 2011 to 2014 with the following two objectives: (1) document spatiotemporal patterns and severity of lesions present in this last remaining Arkansas Ozark Hellbender population, and (2) determine if host factors and infection status are associated with lesion severity. A scoring system was created from 0 to 7 based on lesion observations. Linear mixed model regressions followed by AICc model evaluation were used to determine associations among infection status for amphibian pathogens Batrachochytrium dendrobatidis (Bd) and Ranavirus as well as individual biometrics on lesion score. We discovered 93.2% of Hellbenders had lesions characterized by digit swelling that often progressed toward toe-tip ulceration. In severe cases we observed digital necrosis progressing to digit loss. Any recaptured individuals had the same or worse lesion score from previous captures. The top predictive model for lesion severity included individual mass and Bd infection status with a significant, positive association of Bd with increased lesion severity (β = 0.87 ± 0.39 S.E., C.I.: 0.11, 1.63). Our findings highlight a widespread and progressive disease that is an important factor to consider for the future of Ozark Hellbenders. This syndrome is presumptively multifactorial, and future studies will benefit from investigating several factors of host, infectious agents, and environment and their roles in disease manifestation for the purpose of developing effective, multi-faceted conservation strategies. A summary of potential etiologies and mechanisms is provided that may explain observed lesion distribution and that will be applicable to future disease and epidemiological investigations.

Retrospective analysis of diagnoses and outcomes of 45 cats with micturition disorders presenting as urinary incontinence

Background

In contrast to dogs, the causes and outcomes of urinary incontinence (UI) in cats are largely unknown.

Objectives

To determine the causes, identify comorbid conditions, and assess outcomes of cats with micturition disorders presenting as UI.

Animals

Forty‐five cats with UI.

Methods

Retrospective study. Medical records of cats presented from January 2006 to December 2017 were searched using 45 keywords related to UI. History, presenting complaint, and physical examination findings were used to confirm a diagnosis. Cases were categorized based on functional and anatomic localizations.

Results

Forty‐five cats met inclusion criteria. Spinal cord disease was the most common cause of UI (n = 18), followed by urethral (n = 17), bladder (n = 9), and ureteral (n = 1) disorders. Proportions of voiding and storage phase disorders were similar (53% and 47%, respectively). However, voiding‐phase disorders were observed more frequently in males and younger‐aged cats (P < .03). Urinary tract infection was detected in 11 of 28 (39%) cats. Outcomes were available in 38/45 cases; 16 cats (42%) regained continence, 3 (8%) improved with treatment, and 19 (50%) remained incontinent or were euthanized. Multiple variable logistic regressions indicated that spinal cord disease was significantly more likely to be associated with poor outcomes compared to bladder or urethral disorders (P < .04).

Conclusions and Clinical Importance

Urinary incontinence in cats was associated with a variety of congenital and acquired disorders that affected both phases of micturition with similar frequency. Incontinent cats with spinal cord disorders were common and warrant a more guarded prognosis than do cats with bladder or urethral disorders.