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

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.

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.

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.

Characterization of recessed vulvas in dogs

OBJECTIVE

To determine the prevalence of vulvar recession in a large population of dogs and to compare the reproductive and physical differences between dogs with and without recessed vulvas.

ANIMALS

250 female dogs presenting to a tertiary referral institution.

PROCEDURES

Female dogs > 6 months of age presenting to a tertiary referral institution were enrolled. At enrollment, a full medical history was obtained with particular emphasis on the presence of lower urinary tract (LUT) disease in the 3 months prior to presentation. All dogs underwent a full physical examination including perivulvar cytologic examination and scoring of the degree of perivulvar skin coverage on the basis of an 8-point scale. Dogs with scores of ≥ 7 were classified as having recessed vulvas. When available, urinalysis data were also included.

RESULTS

Recessed vulvas were identified in 36 of 250 (14%) dogs. Dogs with recessed vulvas had significantly higher body condition scores and body weights than unaffected dogs. In addition, recessed vulvas were more common in spayed than sexually intact dogs. Dogs spayed at ≤ 1 year of age were almost 3 times as likely to have vulvar recession, compared with dogs spayed at > 1 year of age. No significant difference was identified between affected and unaffected dogs with respect to the prevalence of LUT signs, urinary tract infections, or perivulvar dermatitis.

CONCLUSIONS AND CLINICAL RELEVANCE

Although recessed vulvas were relatively common in dogs, they did not appear to be associated with an increased risk of LUT disease or perivulvar dermatitis.

Antimicrobial drug resistance profile of isolated bacteria in dogs and cats with urologic problems at Chiang Mai University Veterinary Teaching Hospital, Thailand (2012-2016)

The present study aimed to estimate the proportion of bacterial urinary tract infection (UTI) in dogs and cats, assess risks associated with bacterial UTI, and to determine bacterial isolates' antimicrobial susceptibility and resistance pattern from the urinary tract of dogs and cats with urologic problems. The medical records from animals visiting Chiang Mai University Small Animal Veterinary Teaching Hospital between January 2012 and December 2016 were reviewed. In total, 203 dogs and 49 cats with urinary tract diseases that had samples submitted for bacterial culture were identified;198 and 24 bacterial isolates were recovered from dogs' and cats' submitted samples, respectively. At least one episode of bacterial UTI was detected in 75.4% (95% CI: 69.4-81.3) of dogs and in 40.8% (95% CI: 26.6-55.1) of cats with UTI and submitted urine cultures. Of 242 submitted urinary samples from dogs and 60 urinary samples from cats, bacteria were identified in 74.0% (95% CI: 68.4-79.5) and 38.3% (95% CI: 26.0-50.6), respectively. The most common pathogen of bacteria positive cultured from dogs was Staphylococcus spp. (30.3%), followed by Escherichia coli (16.7%), and Proteus spp. (13.6%). For cats, the most common pathogen was Pseudomonas spp. (25.0%), followed by E. coli (20.8%) and Proteus spp. (16.7%). Staphylococcus spp. isolates from dogs and Proteus spp. isolates from cats were highly susceptible to Amoxicillin/clavulanic acid (AMC) at 88% and 75%, respectively. Of all isolated bacteria, 67.1% of the bacteria from dogs and 83.3% from cats were multidrug-resistant (MDR). The proportion of MDR-bacterial urinary tract infections in dogs and cats with urologic problems in this study was high. This observation raises concerns regarding the potential of zoonotic transmission of MDR-bacteria from these companion animals. The results suggested that AMC remains a good empirical drug for treating UTIs in dogs in this region.

Association between case signalment and disease diagnosis in urinary bladder disease in Australian cats and dogs

Urinary bladder diseases are common in dogs and cats; however, there is little published work on urinary bladder disease in Australian pets. We identified pathology records of Australian dogs and cats with urinary bladder tissue submitted to the University of Queensland Veterinary Laboratory Service during 1994-2016 (n = 320). We described the proportion of bladder diseases in dogs and cats, and applied the less-commonly used logistic regression procedure to quantify associations between signalment variables and disease diagnosis that were evident using descriptive statistics alone. After preliminary analysis, both species were combined because of similar results. Spayed/castrated animals were 74% less likely to be diagnosed with cystitis compared with intact animals. Animals 4-11 y old were also at lower risk of being diagnosed with cystitis compared with younger or older animals. Male animals were at increased risk of neoplasia compared to females, which contrasts with reports from North America and Europe. There was increased risk for developing neoplasia with progressive age, with up to 20 times higher odds in the > 11-y age group. Logistic regression modeling provided unique insight into proportionate morbidity of urinary bladder diseases in Australian dogs and cats.

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.

Risk factors for urinary bacterial growth in dogs with congenital portosystemic shunts: 66 cases (1997-2019)

OBJECTIVE

To identify risk factors for urinary bacterial growth in dogs with confirmed congenital portosystemic shunts on which a quantitative urine culture was performed.

MATERIALS AND METHODS

Sixty-six dogs were included in this retrospective cross-sectional study. Medical records were reviewed from 1997 through 2019. Variables of interest included age, sex and sexual status, clinical signs for a urinary tract infection, blood urea concentration, urinalysis abnormalities, ultrasound abnormalities of the urinary tract, and previous treatment. Univariable and multivariable analyses were performed.

RESULTS

The median age of the dogs was one year (range: 0.2-11.0 years). Urinary tract ultrasound abnormalities (cystic calculi and cystic debris) were reported in 50 dogs (75.7%). Abnormalities on urinalysis included pyuria in nine dogs (13.6%), bacteriuria in 13 dogs (19.7%), and haematuria in 26 dogs (39.4%). The median urine specific gravity was 1.021 (range: 1.004-1.052). Sixteen dogs (24.2%) had a positive quantitative urine culture. Based on multivariable analysis, bacteriuria (Odds ratio, 116; 95% CI, 9.6-1393; P = < 0.001) was the only variable significantly associated with a significantly increased odds for a positive quantitative urine culture.

CLINICAL SIGNIFICANCE

Clinical and subclinical bacteriuria can occur in dogs with congenital portosystemic shunts. In this group of dogs, bacteriuria was a risk factor for urinary bacterial growth.

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.

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.

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.

Recurrent episodes of feline lower urinary tract disease with different causes: possible clinical implications

CASE SERIES SUMMARY

While descriptions of cats with recurrent episodes of feline idiopathic cystitis (FIC) exist, little is published on cats with recurrent episodes of feline lower urinary tract disease (FLUTD) where the cat is diagnosed with different causes of FLUTD at separate episodes. In the present paper, six cats, originally part of larger studies of FLUTD among Norwegian cats, are described. In the project period (2003-2009), these cats had several episodes of FLUTD. At each episode, the cats had a complete physical examination, abdominal imaging, blood work, urinalysis and urine culture performed. Two of the cats initially presented with urolithiasis and subsequently with episodes of non-obstructed FIC. Four of the cats presented with non-obstructed FIC at one or more episodes, but were later diagnosed with urolithiasis or bacterial cystitis without prior catheterisation or other known predisposing factors.

RELEVANCE AND NOVEL INFORMATION

Cats with recurrent episodes of FLUTD may present with different causes at different times. The need to thoroughly work-up cats with recurrent episodes of FLUTD at each presentation is emphasised. FIC may be considered as a predisposing factor in cats developing urolithiasis or bacterial cystitis; alternatively, interrelated FLUTD disease mechanisms exists. Thus, applying multimodal environmental enrichment and modification (MEMO) to cats with signs of FLUTD independent of diagnosis should be considered.

International Society for Companion Animal Infectious Diseases (ISCAID) guidelines for the diagnosis and management of bacterial urinary tract infections in dogs and cats

Urinary tract disease is a common clinical presentation in dogs and cats, and a common reason for antimicrobial prescription. This document is a revision and expansion on the 2011 Antimicrobial Use Guidelines for Treatment of Urinary Tract Disease in Dogs and Cats, providing recommendations for diagnosis and management of sporadic bacterial cystitis, recurrent bacterial cystitis, pyelonephritis, bacterial prostatitis, and subclinical bacteriuria. Issues pertaining to urinary catheters, medical dissolution of uroliths and prophylaxis for urological procedures are also addressed.

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."

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.