Platelet-rich plasma attenuates the UPEC-induced cystitis via inhibiting MMP-2,9 activities and downregulation of NGF and VEGF in Canis Lupus Familiaris model

One of the most prevalent disorders of the urinary system is urinary tract infection, which is mostly brought on by uropathogenic Escherichia coli (UPEC). The objective of this study was to evaluate the regenerative therapeutic and antibacterial efficacy of PRP for induced bacterial cystitis in dogs in comparison to conventional antibiotics. 25 healthy male mongrel dogs were divided into 5 groups (n = 5). Control negative group that received neither induced infection nor treatments. 20 dogs were randomized into 4 groups after two weeks of induction of UPEC cystitis into; Group 1 (control positive; G1) received weekly intravesicular instillation of sodium chloride 0.9%. Group 2 (syst/PRP; G2), treated with both systemic intramuscular antibiotic and weekly intravesicular instillation of PRP; Group 3 (PRP; G3), treated with weekly intravesicular instillation of PRP, and Group 4 (syst; G4) treated with an intramuscular systemic antibiotic. Animals were subjected to weekly clinical, ultrasonographic evaluation, urinary microbiological analysis, and redox status biomarkers estimation. Urinary matrix metalloproteinases (MMP-2, MMP-9) and urinary gene expression for platelet-derived growth factor -B (PDGF-B), nerve growth factor (NGF), and vascular endothelial growth factor (VEGF) were measured. At the end of the study, dogs were euthanized, and the bladder tissues were examined macroscopically, histologically, and immunohistochemically for NF-κB P65 and Cox-2. The PRP-treated group showed significant improvement for all the clinical, Doppler parameters, and the urinary redox status (p < 0.05). The urinary MMPs activity was significantly decreased in the PRP-treated group and the expression level of urinary NGF and VEGF were downregulated while PDGFB was significantly upregulated (p < 0.05). Meanwhile, the urinary viable cell count was significantly reduced in all treatments (P < 0.05). Gross examination of bladder tissue showed marked improvement for the PRP-treated group, expressed in the histopathological findings. Immunohistochemical analysis revealed a marked increase in Cox-2 and NF-κB P65 in the PRP-treated group (P < 0.05). autologous CaCl2-activated PRP was able to overcome the bacterial infection, generating an inflammatory environment to overcome the old one and initiate tissue healing. Hence, PRP is a promising alternative therapeutic for UPEC cystitis instead of conventional antibiotics.

Analysis of lower urinary tract signs and bacteriuria in cats with subcutaneous ureteral bypass systems

Objectives

Distinguishing bacterial cystitis from subclinical bacteriuria is necessary for feline treatment protocols and antimicrobial stewardship. This can be challenging in cats with subcutaneous ureteral bypass (SUB) systems because they may present with lower urinary tract signs without bacteriuria. We investigated the relationship between positive urine culture and lower urinary tract signs in cats with SUBs, including factors associated with each.

Methods

Clinical records were retrospectively reviewed to identify cats presenting with ureteral obstruction that underwent placement of a SUB device(s). The relationship between a positive urine culture and lower urinary tract signs was determined by chi-squared analysis. Univariable and multivariable logistic regression models were performed to identify factors associated with positive urine cultures and lower urinary tract signs.

Results

Two hundred and thirty visits were recorded for 61 cats, with 36 of 230 (16%) positive cultures in 21 of 61 (34%) cats. Lower urinary tract signs were documented at 97 of 230 (42%) visits, with 37 of 61 (61%) cats demonstrating lower urinary tract signs at some point. No relationship was found between culture results and lower urinary tract signs. Risk factors for a positive culture were higher urine pH, higher urine white blood cells and the presence of bacteriuria on microscopy. Risk factors for lower urinary tract signs were younger age and being a purebred cat (vs. non-purebred).

Conclusions

A high proportion of cats with SUBs exhibited sterile lower urinary tract signs, making differentiation between bacterial cystitis and subclinical bacteriuria difficult. This highlights the need for clearer guidelines on when to treat bacteriuria in cats with SUBs.

Population pharmacokinetic analysis of enrofloxacin and its active metabolite ciprofloxacin after intravenous injection to cats with reduced kidney function

BACKGROUND

It is unknown if enrofloxacin accumulates in plasma of cats with reduced kidney function.

HYPOTHESIS

To determine if enrofloxacin and its active metabolite ciprofloxacin have reduced clearance in azotemic cats.

ANIMALS

Thirty-four cats hospitalized for clinical illness with variable degree of kidney function.

METHODS

Prospective study. After enrofloxacin (dose 5 mg/kg) administration to cats, sparse blood sampling was used to obtain 2 compartment population pharmacokinetic results using nonlinear mixed-effects modeling. Plasma enrofloxacin and ciprofloxacin concentrations were measured and summed to obtain the total fluoroquinolone concentration. A model of ciprofloxacin metabolism from enrofloxacin was created and evaluated for covariate effects on clearance, volume of distribution, and the metabolic rate of ciprofloxacin generation from enrofloxacin.

RESULTS

Body weight was the only covariate found to affect total fluoroquinolone volume of distribution (effect 1.63, SE 0.19, P < .01) and clearance (effect 1.63, SE 0.27, P < .01). Kidney function did not have a significant effect on total fluoroquinolone clearance (median 440.8 mL/kg/h (range 191.4-538.0 mL/kg/h) in cats with normal kidney function, 365.8 mL/kg/h (range 89.49-1092.0 mL/kg/h) in cats with moderate kidney dysfunction, and 308.5 mL/kg/h (range 140.20-480.0 mL/kg/h) in cats with severe kidney dysfunction (P = .64). Blood urea nitrogen concentration influenced the metabolic generation of ciprofloxacin from enrofloxacin (effect 0.51, SE 0.08, P < .01), but other markers of kidney function did not.

CONCLUSIONS AND CLINICAL IMPORTANCE

Adjustment of enrofloxacin dosage is not indicated for azotemic cats.

[Urinalysis in dogs and cats, part 2: Urine sediment analysis]

Examination of the urine sediment is part of a routine urinalysis and is undertaken in order to identify insoluble particles in the urine. This procedure is mainly used in the context of diagnostic evaluation of urinary tract diseases, but may also be useful for the diagnosis of systemic diseases and intoxications. Analysis of fresh urine is recommended as changes in cell morphology, cell lysis and in vitro crystal formation may occur in the course of its storage. Manual urine sediment analysis is still performed in many veterinary practices. Native wet-mount preparations are suitable for the identification and quantification of urine sediment particles. The examination of stained wet-mount preparations or air-dried smears may be necessary to further differentiate cells and to identify bacteria. For several years, automatic urine sediment analyzers have been available in veterinary medicine. These save considerable time and staff resources, however verification of the automatically generated results by an experienced observer remains necessary. Urine sediment particles that are frequently identified and clinically relevant include red blood cells, white blood cells, different types of epithelial cells, crystals, and casts as well as bacteria. Furthermore, parasite eggs, fungal hyphae, lipid droplets, spermatozoa, fibres, hair, mucus, plant parts or environmental contaminations may be found in the urine sediment and result in a complication of the result interpretation.

Diabetes Mellitus and the Kidneys

The pathomechanisms implicated in diabetic kidney disease in people are present in dogs and cats and, in theory, could lead to renal complications in companion animals with long-standing diabetes mellitus. However, these renal complications develop during a long period, and there is little to no clinical evidence that they could lead to chronic kidney disease in companion animals.

Bacteriuria in Cystocentesis Samples from Cats in the United Kingdom: Prevalence, Bacterial Isolates, and Antimicrobial Susceptibilities

Bacterial urinary tract infections (UTIs) have historically been reported to be uncommon in cats; however, recent studies showed a higher prevalence. Bacterial UTIs are one of the most common reasons for the use of antimicrobial drugs in veterinary medicine. Our aim was to investigate the prevalence of positive cultures in urine samples submitted to a UK laboratory for testing, as well as prevalence of bacterial species and their antimicrobial susceptibility to commonly used antibiotics. This was a retrospective analysis of positive cultures from feline urine samples collected by cystocentesis submitted over 14 months (January 2018-February 2019). A total of 2712 samples were reviewed, of which 425 documented a positive culture (15.7%) with a total of 444 bacterial isolates. E. coli (43.7%), other Enterobacterales (26.4%), Enterococcus species (14.9%) and Staphylococcus species (9.2%) were the most commonly isolated bacteria. E. coli most commonly showed resistance to cephalexin (20.7%) and amoxicillin (16.7%). Resistance was most commonly seen against amoxicillin (64.1%) and cephalexin (52.2%) in Enterobacterales. Enterococcus species most commonly showed resistance to trimethoprim/sulfamethoxazole (94.3%). Staphylococcus species most commonly showed resistance to amoxicillin (20%). This study showed significant resistance of bacteria found in feline urine samples in the UK to frequently used antibiotics.

Clinical differences in enterococcal bacteriuria compared with other bacteriuria in cats

OBJECTIVES

The clinical differences between Enterococcus species bacteriuria compared with other bacteria has been reported in a small number of cats. The objective of this study was to compare a large number of cats with Enterococcus species bacteriuria to cats with other bacteriuria and determine the clinical differences. It was hypothesized that enterococcal bacteriuria would be associated with subclinical bacteriuria and polymicrobial infections more than other bacteriuria, and that when local or systemic comorbidities were present, enterococcal bacteriuria would be more common.

METHODS

This retrospective case-control study compared case cats with enterococcal bacteriuria to control cats with other bacteriuria. Cats with enterococcal bacteriuria were age, year and weight matched with 1-2 control cats with any other bacteriuria.

RESULTS

Lower urinary tract clinical signs were statistically significantly more common in controls (n = 38/77 [49%]) compared with Enterococcus cases (n = 12/47 [25%]; P = 0.01). Specifically, control cats (n = 20/77 [26%]) were statistically significantly more likely to have gross hematuria compared with Enterococcus case cats (n = 3/47 [6%]; P = 0.01). Enterococcus cases were statistically significantly more likely to have a polymicrobial infection compared with controls (odds ratio 5.84, 95% confidence interval 1.33-34.70; P = 0.01).

CONCLUSIONS AND RELEVANCE

Enterococcus species are associated with subclinical bacteriuria and polymicrobial urinary tract infections in cats vs other bacteriuria.

Urine bacterial culture growth and association with urine sedimentation and clinical findings in cats with acute kidney injury

OBJECTIVES

A urine culture is often pursued in cats with acute kidney injury (AKI) to screen for bacterial growth in the urine, but it can be cost prohibitive. The aim of the study was to determine the ability of a urinalysis and lower urinary tract signs (LUTS) to predict urine culture results in cats with AKI.

METHODS

Ninety-seven cats with AKI were included in this study. This was a retrospective, observational study. Medical records from 2008 to 2018 were reviewed to identify cats with AKI that had a paired urinalysis and urine bacterial culture. The sensitivity, specificity, positive predictive value and negative predictive values of microscopic bacteriuria, pyuria, hematuria and the presence of LUTS for predicting urine culture results was calculated.

RESULTS

Thirty-two percent of cats (n = 31) had a positive urine culture. Of these, 28 (90%) had bacteriuria, 21 (68%) had pyuria, 13 (42%) had hematuria and 10 (32%) had LUTS. Of the 42 cats without hematuria or pyuria, seven had a positive urine culture (17%). Bacteriuria had a high sensitivity (90%) and specificity (92%) for predicting urine culture bacterial growth. The absence of bacteriuria had a high negative predictive value for no bacterial growth (95%). The odds of a positive urine culture were increased with bacteriuria (odds ratio [OR] 114, 95% confidence interval [CI] 29-621; P <0.001), pyuria (OR 21, 95% CI 7-70; P <0.001) and LUTS (OR 5, 95% CI 1.7-16; P = 0.004). Hematuria was not associated with a positive culture (sensitivity 42%, specificity 52%).

CONCLUSIONS AND RELEVANCE

Microscopic bacteriuria and pyuria on urine sediment evaluation and LUTS can be helpful for predicting bacterial culture results in cats with AKI and in settings where submitting a urine culture may not be financially feasible.

Urinary microRNAome in healthy cats and cats with pyelonephritis or other urological conditions

MicroRNAs (miRNAs) are short non-coding RNAs that regulate gene expression at the post-transcriptional level. miRNAs have been found in urine and have shown diagnostic potential in human nephropathies. Here, we aimed to characterize, for the first time, the feline urinary miRNAome and explore the use of urinary miRNA profiles as non-invasive biomarkers for feline pyelonephritis (PN). Thirty-eight cats were included in a prospective case-control study and classified in five groups: healthy Control cats (n = 11), cats with PN (n = 10), cats with subclinical bacteriuria or cystitis (SB/C, n = 5), cats with ureteral obstruction (n = 7) and cats with chronic kidney disease (n = 5). By small RNA sequencing we identified 212 miRNAs in cat urine, including annotated (n = 137) and putative novel (n = 75) miRNAs. The 15 most highly abundant urinary miRNAs accounted for nearly 71% of all detected miRNAs, most of which were previously identified in feline kidney. Ninety-nine differentially abundant (DA) miRNAs were identified when comparing Control cats to cats with urological conditions and 102 DA miRNAs when comparing PN to other urological conditions. Tissue clustering analysis revealed that the majority of urine samples clustered close to kidney, which confirm the likely cellular origin of the secreted urinary miRNAs. Relevant DA miRNAs were verified by quantitative real-time PCR (qPCR). Eighteen miRNAs discriminated Control cats from cats with a urological condition. Of those, seven miRNAs were DA by both RNAseq and qPCR methods between Control and PN cats (miR-125b-5p, miR-27a-3p, miR-21-5p, miR-27b-3p, miR-125a-5p, miR-17-5p and miR-23a-3p) or DA between Control and SB/C cats (miR-125b-5p). Six additional miRNAs (miR-30b-5p, miR-30c, miR-30e-5p, miR-27a-3p, miR-27b-39 and miR-222) relevant for discriminating PN from other urological conditions were identified by qPCR alone (n = 4) or by both methods (n = 2) (P<0.05). This panel of 13 miRNAs has potential as non-invasive urinary biomarkers for diagnostic of PN and other urological conditions in cats.

Prevalence of bacteriuria in cats with neurogenic bladder

Urinary tract infections are defined as the adherence, multiplication, and persistence of an infectious agent within the urogenital system, causing an associated inflammatory response and clinical signs; instead, the presence of bacteria in urine as determined by positive bacterial culture (PUC) from a properly collected urine specimen, in the absence of clinical signs, is defined subclinical bacteriuria. Limited information on the prevalence of PUC in spinal cord injury cats affected by neurogenic bladder (NB) is available. On contrary, in NB dogs and humans the prevalence of bacteriuria is well documented. Moreover, while in humans information about bacteriemia associated with NB is already available, this aspect has never been studied in NB cats. The aim of this prospective study was to determine the prevalence of PUC in cats with NB, compared to animals affected by chronic kidney disease (CKD) and healthy cats. Furthermore, the prevalence of bacteriemia in cats with NB was evaluated. Fifty-one cats met the inclusion criteria: 12 cats were affected by NB, 22 had CKD and 17 were healthy. The prevalence of PUC was 58.33% and 18% in NB and CKD cat populations, respectively. All blood cultures were negative. The incomplete bladder emptying and the decreased resistance in the bladder wall could be considered predisposing elements to PUC in the NB feline population. The results of this study highlight, for the first time, an high prevalence of PUC in cats affected by NB, which was not found to be associated with bacteriemia.

Urinary Cytology: Potential Role in Canine Urinary Tract Infections

The diagnosis of urinary tract infections (UTIs) requires a concomitant evaluation of clinical signs and urine culture, which is of fundamental to start an appropriate antibiotic treatment. Several factors, such as subclinical bacteriuria or pre-analytical errors, may make the interpretation of urine culture difficult. The aim of the study was to evaluate the association between the finding of neutrophils and bacteria in unstained and stained canine urine sediment and the presence of clinical signs and positive urine culture. Urine samples from 35 dogs with clinical signs of UTI and 55 asymptomatic dogs with risk factors for UTI were prospectively collected by cystocentesis, divided into three aliquots, and submitted for: (1) physical and chemical Dipstick analysis and unstained urinary sediment (casts, crystals, bacteria, leucocytes, cells, parasites); (2) stained urinary sediment (extra/intracellular bacteria, degenerated and non-degenerated neutrophils); (3) qualitative and quantitative urine culture and antimicrobial sensitivity-test. The association between unstained and stained findings of urinary sediment and urine culture was tested. Sensibility, specificity, and positive/negative predictive values in diagnosing positive urine cultures of bacteria at unstained and stained evaluation were compared. Both wet-mount bacteriuria and the cytological presence of intracellular and extracellular bacteria, neutrophils, and degenerated neutrophils were successively associated with positive urine culture (p < 0.001). The presence of intracellular bacteria was the only independent predictor of positive urine culture. Total bacterial count did not differ significantly between symptomatic and asymptomatic dogs. Detection of extracellular and intracellular bacteriuria at stained urinary sediment significantly improved the sensibility of predicting positive urine culture. Cytologic evaluation of urinary sediment may be helpful in detecting signs of active inflammation, thus enhancing the clinical relevance of a positive urine culture.

Effect of urine-specific gravity on performance of bacteriuria in predicting urine culture results

OBJECTIVE

To determine the effect of urine-specific gravity (USG) on using microscopic evaluation of bacteriuria to predict urine culture results in dogs and cats.

MATERIALS AND METHODS

We performed a retrospective medical record review of canine and feline patients that had a urinalysis and urine culture performed simultaneously. The sensitivity, specificity, positive predictive value and negative predictive value of microscopic bacteriuria for predicting urine culture results were calculated, stratified by USG. Multivariable regression was performed to test the effect of USG, pyuria, haematuria and species on the agreement between microscopic bacteriuria and culture results.

RESULTS

A total of 481 dogs and 291 cats with paired urinalysis and urine culture results were included in the study. Microscopic bacteriuria had moderate sensitivity (76% in dogs, 64% in cats) and high specificity (97% in dogs, 96% in cats) for predicting urine culture bacterial growth. Samples with rod bacteria were more likely to have bacterial growth than those with cocci (OR=Infinity, 95% CI 4.8 - Infinity). As compared to isosthenuric+hyposthenuric samples (USG ≤1.012), agreement was lower in moderately concentrated (OR=0.44, 95% CI 0.19 to 0.91) samples. Absence of bacteriuria, pyuria and haematuria had a high negative predictive value for no bacterial growth (96%).

CLINICAL SIGNIFICANCE

Microscopic bacteriuria has a high specificity in predicting urine culture results, regardless of USG. The finding that microscopic bacteriuria has better agreement with urine culture results in isosthenuric+hyposthenuric urine argues against reflex culture in these samples, especially if pyuria and haematuria are also absent. Urine microscopy can aid clinicians in determining the likelihood of urine culture growth.

Causes of Death in Stray Cat Colonies of Milan: A Five-Year Report

Simple Summary

Cats have been closely linked to humans for thousands of years. Nowadays, stray cats are frequently hosted in colonies, protected, and enrolled in programs of trap–neuter-–return to control population increase. Italian public veterinary services work in collaboration with voluntary colony caretakers and are responsible for neutering and monitoring the health of colony cats. This retrospective study, conducted by the Anatomical Pathology Unit of the Teaching Veterinary Hospital of Milan in collaboration with the public veterinary services, was undertaken because of the limited information available regarding causes of death of colony cats. The study reports on and statistically analyzes the causes of death of colony cats in the city of Milan as assessed by necropsy. Inflammatory processes including those consistent with the most relevant feline infectious diseases were most common in kittens and young cats. Trauma was more frequent in adult cats, while organ failure was the most common cause of death in aged cats. Considering the possible animal welfare issues deriving from colony cats, awareness of the most common causes of death and collaboration between university veterinary pathologists and public veterinary services represent an essential contribution to health monitoring of colony cats and can assist in the rapid detection of possible emerging animal welfare concerns.

Abstract

The presence of cats in urban environments has a long history. In Italy, stray cats are protected by national and regional laws, and programs of neutering and reintroduction to colonies are ongoing. Colony cats have been widely studied from a behavioral perspective, while surveys regarding their causes of death are limited, although they may provide relevant information related to public health and cat welfare. This retrospective study provides pathological descriptions and statistical analyses of the causes of death of 186 cats from 100 colonies in the city of Milan. Inflammatory processes represent the primary cause of death (37.7%) and include common feline infectious diseases such as feline panleukopenia (67.5%), particularly in kittens, and feline infectious peritonitis (32.5%), most common in adult cats. Trauma was found to be a common cause of death of young/adult cats (14%) with a generally good body condition, while severe parasitosis was less represented (2.6%). The death of old cats was statistically associated with organ failure (24.7%), particularly renal failure, and tumors (11.8%). Knowledge of the most common causes of death of colony cats could make an important contribution to the health monitoring of these cats and sanitary control of their habitats and provide information on possible related emerging animal welfare concerns.

Prevalence of, and factors associated with, positive urine cultures in hyperthyroid cats presenting for radioiodine therapy

OBJECTIVES

Urinary tract infections (UTIs) are reported to be relatively common in hyperthyroid cats, with prevalence rates ranging from 12% to 22%. Factors that are associated with UTIs include age, decreasing body weight and active urine sediments. The purpose of this study was to investigate the prevalence of positive urine cultures (PUCs) in hyperthyroid cats and associated risk factors for PUC.

METHODS

In total, 197 hyperthyroid cats presenting for radioiodine therapy had urine cultures prospectively performed on cystocentesis samples. Data pertaining to clinical signs, drug history, age, weight, blood urea nitrogen, creatinine, serum thyroxine and urinalysis were also evaluated.

RESULTS

The prevalence of PUCs in this population of hyperthyroid cats was 5.1% and all cats were subclinical. Microscopic bacteriuria was significantly associated with a PUC (60%) compared with a negative urine culture (1.6%) status. Age, weight, urine specific gravity <1.020, urine pH, hematuria, pyuria, thyroxine concentration, breed and sex were not associated with PUC status.

CONCLUSIONS AND RELEVANCE

The prevalence of PUCs in this population of cats was lower than previous reports of cats with hyperthyroidism. Cats with a PUC were subclinical at the time of culture, regardless of urine sediment abnormalities. Further studies are necessary to determine the clinical significance of subclinical bacteriuria in hyperthyroid cats.

The association of bacteriuria with survival and disease progression in cats with azotemic chronic kidney disease

BACKGROUND

Cats with chronic kidney disease (CKD) have an increased prevalence of positive urine cultures (PUC). Limited information is available regarding the prognosis of cats with CKD and concurrent PUC.

OBJECTIVE

To determine the association of PUC with survival time and disease progression in cats with CKD.

ANIMALS

Medical records of 509 cats diagnosed with azotemic CKD between 1997 and 2018.

METHODS

Cats were classified as having "no-PUC" or "PUC." The PUC cats were further classified as having 1 or multiple PUC, and also were classified based on the presence or absence of clinical signs of urinary tract infection (UTI). Progression of CKD was defined as a plasma creatinine concentration increase of ≥25% within 365 days of CKD diagnosis; PUC also must have occurred within this time frame. Survival time and frequency of CKD progression were compared between groups.

RESULTS

No significant difference in survival time was found between cats with no-PUC and cats with any number of PUC (P = .91), or between cats with no-PUC, 1 PUC or multiple PUC (P = .37). Also, no significant difference was found in the frequency of CKD progression between PUC and no-PUC cats (P = .5), or among no-PUC, 1 PUC and multiple PUC cats (P = .22). When assessing cats with clinical signs of lower UTI, no significant difference was found in the frequency of CKD progression between cats with true UTI, subclinical bacteriuria or no-PUC (P = .8).

CONCLUSIONS AND CLINICAL IMPORTANCE

When treated with antibiotics, PUC in cats with CKD do not affect disease progression or survival time.

Subclinical bacteriuria in a mixed population of 179 middle-aged and elderly cats: a prospective cross-sectional study

OBJECTIVES

Subclinical bacteriuria (SBU) is the presence of bacteria in urine with no clinical evidence of lower urinary tract disease. The aims of this study were to investigate if being overweight and/or obesity predispose cats to SBU, to investigate previously reported risk factors and to determine the prevalence of SBU in a prospectively sampled cohort of middle-aged and elderly cats.

METHODS

Cats aged ⩾6 years presenting to the University Hospital for Companion Animals in Copenhagen from 2015-2019 for causes unrelated to the lower urinary tract were eligible for enrolment. Body condition scoring was performed on a 9-point scale. Overweight was defined as a body condition score (BCS) ⩾6 and obese as a BCS ⩾8. The correlation between SBU and the variables of sex, healthy/diseased, age, BCS and comorbidities (chronic kidney disease, diabetes mellitus, hyperthyroidism, hepatic disorders and gastrointestinal disease) were analysed by binominal logistic regression.

RESULTS

In total, 179 cats ranging from 6-20 (median 10) years of age were included. SBU was identified in 11/179 cats (6.1%). Being overweight was not a significant risk factor (overweight/obese odds ratio [OR] 0.3, 95% confidence interval [CI] 0.06-1.6, relative risk [RR] 0.3 [95% CI 0.05-1.3] vs lean; P = 0.2) and neither was obesity compared with lean and overweight cats (P = 0.99). Female sex (OR 6.2 [95% CI 1.3-30], RR 4.7 [95% CI 1.5-12] vs male; P = 0.02) and the presence of hepatic disease (OR 7.5 [95% CI 1.4-39], RR 5.3 [95% CI 1.3-12]; P = 0.02) were significant risk factors.

CONCLUSIONS AND RELEVANCE

The prevalence of SBU in cats is low, and being overweight/obese was not identified as a predisposing factor. The increased risk associated with hepatic disease has not been previously reported, and further studies are needed to confirm this finding.

Pilot study of side effects and serum and urine concentrations of amoxicillin-clavulanic acid in azotemic and non-azotemic cats

OBJECTIVES

The aims of this study were to determine the side effect frequency and serum and urine drug concentrations of amoxicillin-clavulanic acid in cats with and without azotemic chronic kidney disease (azCKD).

METHODS

Owners whose cats had been prescribed amoxicillin-clavulanic acid completed a survey regarding the occurrence and type of side effects, and whether treatment was altered as a result. Cats were defined as azCKD (serum creatinine concentration >2.0 mg/dl, urine specific gravity [USG] <1.035 with a clinical diagnosis of chronic kidney disease) and without azCKD (serum creatinine concentration <2.0 mg/dl). Data were assessed with Fisher's exact test. Serum and urine samples were obtained from client-owned cats with azCKD (n = 6) and without azCKD (n = 6, serum creatinine concentration <1.8 mg/dl, USG >1.035) that were receiving amoxicillin-clavulanic acid. Amoxicillin and clavulanic acid were measured with liquid chromatography coupled to tandem mass spectrometry and compared between groups with a Mann-Whitney test. Correlation between serum creatinine and drug concentrations in urine and serum was determined using Spearman's rank test.

RESULTS

Sixty-one surveys were returned (11 azCKD cats and 50 without azCKD cats). No significant difference in the presence of side effects or type of side effects was seen between groups; however, significantly more azCKD cats had more than one side effect (P = 0.02). More owners of azCKD cats reported that an alteration in treatment plan was necessitated by side effects (55% vs 12%; P = 0.008). Urine amoxicillin was significantly lower in cats with azCKD (P = 0.01) and serum amoxicillin trended toward significance (P = 0.07). Serum amoxicillin concentration was positively correlated with serum creatinine (P = 0.02; r = 0.62) and urine amoxicillin concentration was negatively correlated with serum creatinine (P = 0.01; r = -0.65).

CONCLUSIONS AND RELEVANCE

The data suggest that cats with azCKD have altered pharmacokinetics of amoxicillin, which may contribute to an increased incidence of multiple side effects.

Hyperthyroidism is not a risk factor for subclinical bacteriuria in cats: A prospective cohort study

Background

Subclinical bacteriuria is defined as a positive bacterial urine culture in the absence of clinical evidence of urinary tract infection (UTI). Studies have reported that hyperthyroid cats have UTIs (mostly subclinical) with prevalence rates of 12%‐22%. Consequently, clinicians consider hyperthyroidism a risk factor for development of subclinical bacteriuria, and many recommend urine culture when evaluating hyperthyroid cats.

Objectives

To compare the prevalence of subclinical bacteriuria (based on positive urine culture) in untreated hyperthyroid cats to that in euthyroid cats of similar age and sex.

Animals

Three hundred and ninety‐three hyperthyroid cats presented for radioiodine treatment and 131 euthyroid cats (≥7 years of age) presented for routine examination. Cats with signs of lower urinary tract disease were excluded.

Methods

Prospective cohort study. Both hyperthyroid and euthyroid cats had urine collected by cystocentesis for complete urinalysis and culture. Data pertaining to age, sex, body condition, and serum thyroxine and creatinine concentrations also were acquired. Logistic regression was performed to evaluate for potential risk factors for subclinical bacteriuria.

Results

Hyperthyroid cats showed a low prevalence of subclinical bacteriuria (4.3%), which did not differ from that found in euthyroid cats (4.6%). Of the signalment factors evaluated, only female sex was a significant risk factor (odds ratio [OR], 6.9; P = .002). Furthermore, positive urine cultures were more likely in specimens with dilute urine concentration (<1.035), pyuria, or microscopic bacteriuria.

Conclusions and Clinical Importance

Hyperthyroid cats are not at risk for subclinical bacteriuria. In the absence of lower urinary tract signs, no clinical benefit exists in routinely performing urine cultures when evaluating hyperthyroid cats.

Prevalence and risk factors of feline lower urinary tract disease in Chiang Mai, Thailand

Feline lower urinary tract disease (FLUTD) is a common problem in cats. The objectives of the study were to determine the prevalence, clinical signs, and causes of FLUTD and the risk factors for FLUTD. The medical records of 3486 cats visiting Chiang Mai University Small Animal Veterinary Teaching Hospital (VTH) between November 2016 and October 2017 were reviewed. An age-matched case-control study was performed to determine the risk factors for FLUTD by comparing 78 cats with FLUTD and 78 clinically normal age-matched cats. For each animal, potential risk data were obtained from medical records and cat owner interviews; these were analysed for associations with FLUTD. Multivariable logistic regression analysis was performed to estimate the odds ratios and to adjust for expected confounding factors. The prevalence of FLUTD in cats visiting the Chiang Mai University Veterinary Teaching Hospital was 2.2%. The most common clinical signs identified were urethral obstruction (55.1%) and haematuria (23.1%). The most common diagnoses were feline idiopathic cystitis (FIC) (57.7%) and urolithiasis (struvite) (18%). The multivariable logistic regression analysis results indicated that FLUTD was most likely to be diagnosed in castrated male cats. FIC and urolithiasis were the most common diagnoses in cats with FLUTD, and male sex and castration increased the risk of FLUTD.

A clinical approach to multidrug-resistant urinary tract infection and subclinical bacteriuria in dogs and cats

Multidrug-resistant bacteria are increasingly isolated from the urinary tract of pets, particularly those that suffer from concurrent conditions, have been hospitalised, or were treated with antimicrobials in the recent past. Many of the multidrug-resistant bacteria encountered are resistant to all commonly used oral antibiotics. This poses both a therapeutic dilemma in the individual pet and a threat to public health. This article begins with an overview of multidrug resistance in organisms that are commonly isolated from the urinary tract of pets. This is followed by a proposed clinical approach to managing multidrug-resistant urinary bacteria, which summarises current knowledge regarding appropriate sampling and analysis, reviews the current guidelines regarding appropriate antimicrobial use and discusses treatment options that might be considered. The article highlights several shortcomings of the current knowledge to be considered when planning future clinical research and developing policies.

Stability and profiling of urinary microRNAs in healthy cats and cats with pyelonephritis or other urological conditions

Background

Specific biomarkers of pyelonephritis (PN) in cats are lacking. MicroRNAs (miRNAs) have diagnostic potential in human nephropathies.

Objectives

To investigate the presence/stability of miRNAs in whole urine of cats and the discriminatory potential of selected urinary miRNAs for PN in cats.

Animals

Twelve healthy cats, 5 cats with PN, and 13 cats with chronic kidney disease (n = 5), subclinical bacteriuria (n = 3), and ureteral obstructions (n = 5) recruited from 2 companion animal hospitals.

Methods

Prospective case‐control study. Expression profiles of 24 miRNAs were performed by quantitative PCR (qPCR). Effect of storage temperature (4°C [24 hours], −20°C, and −80°C) was determined for a subset of miRNAs in healthy cats.

Results

Urinary miR‐4286, miR‐30c, miR‐204, miR4454, miR‐21, miR‐16, miR‐191, and miR‐30a were detected. For the majority of miRNAs tested, storage at 4°C and −20°C resulted in significantly lower miRNA yield compared to storage at −80°C (mean log2fold changes across miRNAs from −0.5  ± 0.4 SD to −1.20 ± 0.4 SD (4°C versus −80°C) and from −0.7 ± 0.2 SD to −1.20 ± 0.3 SD (−20°C versus −80°C)). Cats with PN had significantly upregulated miR‐16 with a mean log2fold change of 1.0 ± 0.4 SD, compared with controls (−0.1 ± 0.2, P = .01) and other urological conditions (0.6 ± 0.3, P = .04).

Conclusions

Upregulation of miR16 might be PN‐specific, pathogen‐specific (Escherichia coli), or both.

Urinary tract infection and subclinical bacteriuria in cats: A clinical update

PRACTICAL RELEVANCE

Urinary tract infection (UTI) is an important cause of feline lower urinary tract disease (FLUTD), particularly in female cats older than 10 years of age. In addition to cats with typical clinical signs of FLUTD or upper UTI, many cats have subclinical bacteriuria, but the clinical relevance of this is currently uncertain. UTIs are one of the most important indications for antimicrobial use in veterinary medicine and contribute to the development of antimicrobial resistance. Adherence to treatment guidelines and confinement to a few first-line antimicrobial agents is imperative to avoid further deterioration of the antimicrobial resistance situation. The decision to treat with antimicrobials should be based on the presence of clinical signs, and/or concurrent diseases, and the results of urine culture and susceptibility testing.

CLINICAL CHALLENGES

Distinguishing between cats with bacterial cystitis, and those with idiopathic cystitis and concurrent clinical or subclinical bacteriuria, is challenging, as clinical signs and urinalysis results may be identical. Optimal treatment of subclinical bacteriuria requires clarification as there is currently no evidence that demonstrates a beneficial effect of routine treatment. Management of recurrent UTIs remains a challenge as evidence for most alternatives used for prevention in cats is mainly anecdotal, and no preventive treatment modality is currently recommended.

EVIDENCE BASE

This review draws on an extensive literature base in veterinary and human medicine, including the recently updated guidelines of the International Society for Companion Animal Infectious Diseases for the diagnosis and management of bacterial urinary tract infections in dogs and cats. Where published evidence is lacking, the authors describe their own approach; notably, for the bacteriuric cat with chronic kidney disease.

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.

Frequency of bacteriuria in dogs with chronic kidney disease: A retrospective study of 201 cases

Background

Studies have shown an increased prevalence of positive urine culture (PUC) in cats with chronic kidney disease (CKD); no information is available in dogs.

Objectives

To document the PUC frequency in a cohort of dogs with CKD, determine risk factors for PUC, and identify associations between clinicopathologic data and PUC.

Animals

Two hundred one client‐owned dogs with CKD.

Methods

Retrospective, observational study. Dogs recruited from 2 veterinary teaching hospitals were included if they were diagnosed with CKD and had a culture performed on urine collected by cystocentesis. The PUC frequency was calculated, multivariate analysis was performed to identify risk factors, and associations with clinicopathologic data were investigated.

Results

Sixty‐five dogs (32%) with CKD had PUC, including 8 (28%) in International Renal Interest Society (IRIS) stage 1; only 8% showed signs of a urinary tract infection. Escherichia coli was the most common isolate (67%). A PUC was more likely in females (odds ratio [OR], 3.22; 95% confidence interval [CI], 1.67‐6.37; P < .001) than males and in dogs with isosthenuria (OR, 2.48; 95% CI, 1.24‐5.03; P = .01) than in dogs with urine‐specific gravity 1.013‐1.024. A positive leukocyte esterase test and microorganisms found by urine sediment analysis were significantly associated with PUC (both P < .001).

Conclusions and Clinical Importance

Dogs with CKD, even IRIS stage 1, have a high frequency of PUC and most cases are asymptomatic. A urine culture could be considered in the routine evaluation of dogs with CKD, but the clinical relevance of a PUC remains unknown and needs further evaluation.

Urinary Tract Infection

"Urinary tract infection (UTI) is a common diagnosis in companion animal practice and is responsible for a significant proportion of antimicrobial use in veterinary medicine. The veterinary community has begun to follow the standards of care in human medicine and shift its definition of an UTI based on culture results and toward the presence of lower urinary tract symptoms. An improved understanding of the pathophysiology of UTI, risk factors for clinical disease, and the implementation of more reliable in-house diagnostic testing can lead to improved outcomes for patients and reduce inappropriate treatment. Investigation of antibiotic-sparing therapies holds some promise as well."

Risk factors for positive urine cultures in cats with subcutaneous ureteral bypass and ureteral stents (2010-2016)

Background

Ureteral stent and subcutaneous ureteral bypass (SUB) placement are commonly used for managing ureteral obstructions. Urinary tract infection (UTI) is a recognized complication.

Objectives

To determine postoperative incidence of positive urine cultures in cats undergoing ureteral stent and SUB placement and to identify risk factors associated with positive urine cultures.

Design

Retrospective study.

Animals

Forty‐three cats that underwent 48 surgical events.

Procedures

Medical records were reviewed. Cats were included if urine cultures were performed before and after surgery. Variables were compared to identify risk factors.

Results

Urine cultures were positive postoperatively pre‐discharge in 5/20 (25%) cats. Median duration of follow‐up post‐discharge was 209 days (range, 11‐2184 days), with a total of 143 urine cultures performed in cats post‐discharge. Of these, 16 (11%) were positive in 12/48 (25%) cats. Nine different bacteria were identified; Enterococcus spp. (n = 8) predominated as monomicrobic or mixed infections. In 14/16 instances of positive urine cultures, affected cats had lower urinary tract signs, signs of pyelonephritis or both. Cats that received antibiotics postoperatively were significantly less likely to have a positive urine culture compared to those that did not (odds ratio, 0.2, 95% confidence interval, 0.05, 0.8, P = 0.02). Chronic kidney disease, renal implant type and postoperative urinary catheterization were not associated with positive urine cultures.

Conclusions and Clinical Relevance

Postoperatively, occurrence of positive urine cultures was similar to previous reports. Subclinical bacteriuria was less common than UTI. Postoperative urinary catheterization has been speculated to increase risk of bacteriuria, but this was not the case in this cohort.

Prevalence of feline urinary tract pathogens and antimicrobial resistance over five years

The aim of this retrospective study was to document the prevalence of bacterial species in cats with significant bacteriuria and to compare their antimicrobial susceptibilities over five years. One hundred sixty-nine positive urine cultures from 150 cats were included. Fifty-five per cent showed clinical signs, while 40 per cent had subclinical bacteriuria. Escherichia coli, Staphylococcus species, Enterococcus species, Streptococcus species and Proteus mirabilis accounted for 50.5 per cent, 22.9 per cent, 15,1 per cent, 3.6 per cent and 2.6 per cent, respectively. Enterococcus species was significantly more common in cats with subclinical bacteriuria. Enterococcus species and Proteus mirabilis isolates were resistant to a significantly higher number of antimicrobials than other isolates. Applying the formula to select rational antimicrobial therapy, bacterial isolates were most likely to be susceptible to imipenem, nitrofurantoin, gentamicin and amoxicillin clavulanic acid. Over the study period, only minor differences were noted for the antimicrobial impact factors (IFs) between years and between cats with and without clinical signs. The cumulative IF increased significantly compared with the previous 10 years. Empirical treatment of bacterial cystitis should be avoided whenever possible and, if needed, based on the locally determined bacterial spectrum and antibiotic susceptibility.

Subclinical Bacteriuria in Older Cats and its Association with Survival

Background

Bacterial urinary tract infections are uncommon in cats in general but the prevalence increases to 29% in older cats with comorbidities (Veterinary Clinical Pathology 2008, 37, 317; Journal of Feline Medicine & Surgery 2007, 9, 124; Veterinary Microbiology 2009, 136, 130). Frequently, the infections are subclinical. The clinical relevance of subclinical bacteriuria (SB) is uncertain, and the optimal treatment requires clarification.

Objective

Prospective, observational study to: (i) identify the prevalence and incidence count of SB in older (≥7 years), nonazotemic cats, (ii) evaluate specific risk factors for SB, and (iii) investigate the potential relationship between untreated SB and survival.

Animals

Sixty‐seven, nonazotemic cats were tested on 5 occasions over 3 years.

Methods

Urine samples were obtained by cystocentesis for quantitative urine culture and blood samples for measurement of serum creatinine concentration. Episodes of SB were not treated. Serum creatinine concentration, body weight, urine specific gravity, sex, and age were evaluated as potential risk factors for a positive urine culture. The association between urine culture results and survival was evaluated with Cox's proportional hazard model.

Results

A total of 256 urine samples was obtained. The prevalence of SB varied between 10 and 13%, and incident infections were uncommon. Female cats were 21 times more likely to have a positive urine culture than were male cats (odds ratio [OR], 21.2; confidence interval [CI], 4.1–110; P = .00028). Subclinical bacteriuria was not significantly associated with survival.

Conclusion and clinical importance

Subclinical bacteriuria is common in nonazotemic, older cats. Although antimicrobial treatment was withheld, the presence of SB was not adversely associated with survival.

Bakterielle Harnwegsinfektionen bei Katzen

Ziel: Ermittlung der Prävalenz prädisponierender Begleiterkrankungen (BE) bei Katzen mit bakteriellen Harnwegsinfektionen (HWI) und der Prävalenz von Bakterienspezies bei verschiedenen BE sowie deren Sensibilität gegenüber den bei HWI häufig eingesetzten Antibiotika Doxycyclin, Trimethoprim-Sulfamethoxazol (TMS), Amoxicillin-Clavulansäure (AMC), Cephalothin und Enrofloxacin. Material und Methoden: In die retrospektive Studie wurden Katzen mit positiver Urinkultur im Zeitraum 2003–2009 eingeschlossen. Basierend auf den Daten der Krankenakten erfolgte eine Einteilung in vier Gruppen: Katzen mit systemischen prädisponierenden BE, Katzen mit lokalen prädisponierenden BE, Katzen mit Harnblasendauerkathetern (HBDK) und Katzen ohne dokumentierte BE. Zur Ermittlung der wahrscheinlichen Effektivität der Antibiotika wurden deren antimikrobielle Impact-Faktoren berechnet. Ergebnisse: In die Studie gingen 194 Katzen mit 219 bakteriellen Isolaten ein. Davon wiesen 78,4% (152/194) eine BE auf. 49,5% (96/194) hatten eine systemische BE und 28,9% (56/194) hatten eine lokale BE oder einen HBDK. Katzen mit systemischen BE waren signifikant älter als Katzen der anderen Gruppen und häufiger weiblich als Katzen mit lokaler BE und HBDK. Mehr als 50% der Katzen mit systemischer BE zeigten keine klinischen Symptome einer Erkrankung des unteren Harntrakts. Escherichia (E.) coli, gefolgt von Streptococcus spp., Staphylococcus spp. und Enterococcus spp. waren die am häufigsten vorkommenden Isolate. Dabei lag der Anteil der E.-coli-Isolate bei Katzen mit systemischer BE signifikant höher, während bei Katzen mit HBDK und Katzen mit anderen lokalen BE der Anteil an Streptococcus- und Staphylococcus-spp.-Isolaten signifikant höher war. Bei Katzen mit lokaler BE und Katzen mit HBDK ergaben sich niedrigere antimikrobielle Impact-Faktoren als bei Katzen der anderen Gruppen. Schlussfolgerung und klinische Relevanz: Ein Großteil der Katzen mit HWI leidet unter einer prädisponierenden BE. Katzen mit systemischer BE zeigen häufig keine Symptome einer Erkrankung des unteren Harntrakts. AMC und TMS waren in dieser Katzenpopulation die Antibiotika mit den höchsten antimikrobiellen Impact-Faktoren.

Subclinical bacteriuria in cats: prevalence, findings on contemporaneous urinalyses and clinical risk factors

Objectives Subclinical bacteriuria (SB) is bacterial colonization of the urinary tract in the absence of clinical signs. The purposes of this study were to determine the prevalence of SB in cats and to describe results of the contemporaneous urinalysis. Secondarily, patient characteristics associated with SB were compared with those for cats without SB. Methods An electronic search identified all urine cultures performed on cats at a teaching hospital between 2009 and 2015. Results were subcategorized based on the presence or absence of lower urinary tract disease (LUTD) and SB-positive cases identified. The first control population was from samples without LUTD. The second control population was from all samples not identified as a SB-positive sample, including subclinical negative samples and those with LUTD. Five controls for each SB-positive sample were selected for both control groups. Medical records for all groups were reviewed. Results In all, 31/500 (6.2%) subclinical samples were positive. Most infections were a single organism (n = 27); four contained multiple organisms. Escherichia coli was the most common species (58%) followed by Enterococcus species (25%). Positive specimens were more likely to be from female cats (n = 24) vs male (n = 7; P = 0.0054). SB was strongly associated with bacteriuria (60% vs 6%; P <0.0001) and pyuria (67% vs 19%; P <0.0001). Positive specimens were significantly more likely to have an abnormal sediment examination (odds ratio 13.5, P <0.0001). When compared with all specimens including those with LUTD, SB was significantly associated with a lower urine specific gravity (1.022 vs 1.030; P = 0.0256) and presence of chronic kidney disease (68% vs 46%; P = 0.0168). Conclusions and relevance In this study, SB appears to be uncommon in cats and, in most cases, is associated with an abnormal urine sediment examination. Based on this study, there is little indication to perform a culture in a cat with no clinical signs of LUTD and an unremarkable sediment examination.

A real-time reporting system of causes of death or reasons for euthanasia: A model for monitoring mortality in domesticated cats in Taiwan

A novel, real-time mortality recording system was designed to collect mortality data in companion animals from veterinary hospitals in Taiwan. This retrospective study aims to introduce the system, and to utilize the data collected for further investigation of the lifespan and mortality of the domesticated cat population stratified by demographic variables. Our data revealed that 1325 domesticated cats were acquired between 2012 and 2014. The median age of the study population was 8.0 years (IQR 3.0–13.0; range 0.0–22.7). Neutered and purebred cats lived longer. The most common causes of death were renal and urologic disorders, followed by neoplasia, infection, cardiovascular disorders, and trauma. Independent factors for common causes were surveyed. Advanced age and neutering was found to be associated with death due to renal and urologic disorders as well as with neoplasia. In contrast, younger age was found to be associated with death due to trauma and infection; being unneutered and living in the capital city were found to be associated with death due to trauma. Being male or purebred was found to be associated with death due to cardiovascular disorders.

Current Understanding of the Pathogenesis of Progressive Chronic Kidney Disease in Cats

In cats with chronic kidney disease (CKD), the most common histopathologic finding is tubulointerstitial inflammation and fibrosis. However, these changes reflect a nonspecific response of the kidney to any inciting injury. The risk of developing CKD is likely to reflect the composite effects of genetic predisposition, aging, and environmental and individual factors that affect renal function over the course of a cat's life. However, there is still little information available to determine exactly which individual risk factors predispose a cat to develop CKD. Although many cats diagnosed with CKD have stable disease for years, some cats show overtly progressive disease.

Strengths and Limitations of Model Systems for the Study of Urinary Tract Infections and Related Pathologies

Urinary tract infections (UTIs) are some of the most common bacterial infections worldwide and are a source of substantial morbidity among otherwise healthy women. UTIs can be caused by a variety of microbes, but the predominant etiologic agent of these infections is uropathogenic Escherichia coli (UPEC). An especially troubling feature of UPEC-associated UTIs is their high rate of recurrence. This problem is compounded by the drastic increase in the global incidence of antibiotic-resistant UPEC strains over the past 15 years. The need for more-effective treatments for UTIs is driving research aimed at bettering our understanding of the virulence mechanisms and host-pathogen interactions that occur during the course of these infections. Surrogate models of human infection, including cell culture systems and the use of murine, porcine, avian, teleost (zebrafish), and nematode hosts, are being employed to define host and bacterial factors that modulate the pathogenesis of UTIs. These model systems are revealing how UPEC strains can avoid or overcome host defenses and acquire scarce nutrients while also providing insight into the virulence mechanisms used by UPEC within compromised individuals, such as catheterized patients. Here, we summarize our current understanding of UTI pathogenesis while also giving an overview of the model systems used to study the initiation, persistence, and recurrence of UTIs and life-threatening sequelae like urosepsis. Although we focus on UPEC, the experimental systems described here can also provide valuable insight into the disease processes associated with other bacterial pathogens both within the urinary tract and elsewhere within the host.

ISFM Consensus Guidelines on the Diagnosis and Management of Feline Chronic Kidney Disease

PRACTICAL RELEVANCE

Chronic kidney disease (CKD) is one of the most commonly diagnosed diseases in older cats. In most cats, CKD is also a progressive disease and can be accompanied by a wide range of clinical and clinicopathological changes. These ISFM Consensus Guidelines have been developed by an independent panel of clinicians and academics to provide practical advice on the diagnosis and management of this complex disease.

CLINICAL CHALLENGES

Although CKD is a common clinical problem in cats, the manifestations of disease vary between individuals. Thus there is a need for careful and repeat evaluation of cats with CKD and adjustment of therapy according to individual needs. In addition to addressing problems arising from CKD and improving quality of life (QoL) for the patient, therapy may also target slowing the underlying progression of disease and hence prolonging life. While maintaining QoL is of paramount importance in our patients, this can be challenging when multiple therapies are indicated. In some cases it is necessary to prioritise therapy, given an understanding of what is likely to most benefit the individual patient.

EVIDENCE BASE

In preparing these Guidelines, the Panel has carefully reviewed the existing published literature, and has also graded the quality of evidence for different interventions to help to provide practical recommendations on the therapeutic options for feline CKD. This is a field of veterinary medicine that has benefited from some excellent published clinical research and further research findings will undoubtedly modify the recommendations contained in these Guidelines in the future.

Chronic Kidney Disease in Aged Cats: Clinical Features, Morphology, and Proposed Pathogeneses

Chronic kidney disease (CKD) is the most common metabolic disease of domesticated cats, with most affected cats being geriatric (>12 years of age). The prevalence of CKD in cats exceeds that observed in dogs, and the frequency of the diagnosis of CKD in cats has increased in recent decades. Typical histologic features include interstitial inflammation, tubular atrophy, and fibrosis with secondary glomerulosclerosis. In contrast to people and dogs, primary glomerulopathies with marked proteinuria are remarkably rare findings in cats. Although a variety of primary renal diseases have been implicated, the disease is idiopathic in most cats. Tubulointerstitial changes, including fibrosis, are present in the early stages of feline CKD and become more severe in advanced disease. A variety of factors-including aging, ischemia, comorbid conditions, phosphorus overload, and routine vaccinations-have been implicated as factors that could contribute to the initiation of this disease in affected cats. Factors that are related to progression of established CKD, which occurs in some but not all cats, include dietary phosphorus intake, magnitude of proteinuria, and anemia. Renal fibrosis, a common histologic feature of aged feline kidneys, interferes with the normal relationship between peritubular capillaries and renal tubules. Experimentally, renal ischemia results in morphologic changes similar to those observed in spontaneous CKD. Renal hypoxia, perhaps episodic, may play a role in the initiation and progression of this disease.

Feline urinary tract pathogens: prevalence of bacterial species and antimicrobial resistance over a 10-year period

The purpose of this retrospective study was to identify bacterial species in cats with bacterial urinary tract infections (UTIs) and to investigate their antimicrobial susceptibilities over a 10-year period. Three hundred and thirty cultures from 280 cats were included in the study. The mean age of affected cats was 9.9 years; female cats with bacterial UTIs were significantly older than male cats with UTIs. The most common pathogen identified was Escherichia coli (42.3 per cent), followed by Streptococcus species (19.3 per cent), Staphylococcus species (15.6 per cent), Enterococcus species (6.6 per cent) and Micrococcaceae (5.8 per cent). Forty specimens (12.1 per cent) yielded growth of more than one isolate. Streptococcus and Enterococcus isolates were resistant to a significantly higher number of antimicrobial agents than E coli and Staphylococcus species isolates. Applying the formula to select rational antimicrobial therapy, bacterial isolates were most likely to be susceptible to nitrofurantoin, amoxicillin clavulanic acid, enrofloxacin and gentamicin. The antimicrobial impact factor for nitrofurantoin increased significantly over the 10-year period, whereas there was no significant change in antimicrobial impact factors for doxycycline, trimethoprim-sulfamethoxazole, gentamicin, enrofloxacin, cephalothin and amoxicillin clavulanic acid. The detected changes in in vitro antimicrobial efficacy could help to develop hospital-specific guidelines for antimicrobial use to prevent the further development of resistance in feline uropathogens.

Hyperammonaemia in four cats with renal azotaemia

Hyperammonaemia is well reported in animals with advanced hepatic disease and portosystemic shunts, but is unreported in cats with renal disease. This case series describes four cats with severe renal azotaemia in which elevated ammonia levels were detected during the course of treatment. In two cases hyperammonaemia was detected at a time when neurological signs consistent with encephalopathy had developed. This raises the possibility that hyperammonaemia may play a role in the development of encephalopathy in cats with renal azotaemia.

Genetic and phenotypic characterisation of Escherichia coli producing cefotaximase-type extended-spectrum β-lactamases: first evidence of the ST131 clone in cats with urinary infections in Italy

The incidence of cefotaximase (CTX-M)-type extended-spectrum β-lactamase (ESBL)-producing Escherichia coli has increased dramatically in humans and animals since the middle of the last century. E coli that produce CTX-M β-lactamase represent a major cause of urinary tract infections, and pose a significant therapeutic challenge to both human and veterinary medicine. As data on uropathogenic CTX-M-producing strains in cats are limited, the aim of this study was to describe the genetic character and antibiotic resistance phenotypes of CTX-M-producing E coli isolated from cats with cystitis. Seven of 15 E coli bacteria isolated from 138 urine samples had the CTX-M gene and were therefore included in this study. These isolates were screened by polymerase chain reaction for the presence of 14 extra-intestinal virulence factors, class 1 and class 2 integrons, and to identify their phylogenetic groups. Multi-locus sequence typing (MLST) of the strains and susceptibility testing (disc diffusion method) were also performed. Virulence factor iutA was the most frequent determinant identified (86.7%), and the majority of CTX-M-producing strains (n = 5) carried class 1 integrons. MLST allowed us to discriminate four known sequence types (ST131, ST555, ST602, ST155) and three novel sequence types (ST3847, ST3848, ST4181). To the best of our knowledge, this is the first study to report uropathogenic CTX-M-producing E coli ST131 in cats in Italy. Accurate diagnostics and prudent use of antimicrobials are recommended to avoid the spread of multidrug-resistant pathogens in veterinary medicine and to prevent their transmission to humans.

Feline CKD: Diagnosis, staging and screening - what is recommended?

PRACTICAL RELEVANCE

Feline chronic kidney disease (CKD) is frequently encountered by veterinarians. Timely diagnosis and staging may facilitate the initiation of adequate therapy and improve the prognosis for patients.

CLINICAL CHALLENGES

Feline CKD is diagnosed based on the presence of compatible clinical signs and renal azotaemia, which implies that urinalysis (particularly urine specific gravity) is mandatory to confirm the diagnosis. Although the diagnosis of advanced feline CKD and associated complications is usually straightforward, based on complete blood and urine examination, all routine blood and urine tests have their limitations in detecting early CKD. Therefore, diagnosing early or non-azotaemic CKD is much more challenging. Although determination of glomerular filtration rate (GFR) would be ideal to identify early kidney dysfunction, practical limitations hamper its routine use in clinical practice.

PATIENT GROUP

CKD is typically a disease of aged cats, but may affect cats of all ages. Conclusive breed and sex predispositions for feline CKD are not reported.

AUDIENCE

This review is directed at practising veterinarians and provides an overview of the required diagnostic tests, the classification system established by the International Renal Interest Society, and the importance of and possible techniques for early detection of CKD.

EVIDENCE BASE

Staging of cats with CKD is essential as it directs management and provides a prognostic guide. Given that diagnosis at early disease stages is associated with more prolonged survival times, simple, inexpensive and accurate methods for early CKD diagnosis are needed. Techniques currently under investigation include limited sampling strategies to estimate GFR, clearance marker cut-off concentrations to identify cats with low GFR, new indirect GFR markers and urinary biomarkers.