Volume 37 | Issue 3 (September 2008)
Evaluation of urine specific gravity and urine sediment as risk factors for urinary tract infections in catsVet Clin Pathol. September 2008;37(3):317-22.1 Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA.
AbstractBACKGROUND: It has been suggested that diseases that promote isosthenuria predispose to urinary tract infections because of a lack of the common bacteriostatic properties present in concentrated urine. OBJECTIVES: The purpose of this study was to assess the clinicopathologic risk factors for positive urine culture outcome in cats with chronic kidney disease (CKD), diabetes mellitus (DM), uncontrolled hyperthyroidism (HT), or lower urinary tract disease (LUTD). METHODS: For this retrospective study, medical records of all cats in which a urinalysis and aerobic bacterial urine culture were performed between January 1995 and December 2002 were reviewed. Signalment, body weight, and clinicopathologic data were recorded. Based on the medical records, cats were diagnosed with CKD, DM, HT, or LUTD. Prevalence odds ratios and 95% confidence intervals were calculated using logistic regression. Multivariate models were created for each variable of interest while controlling for the confounding effect of disease group. RESULTS: Six hundred fourteen cats met the criteria for inclusion in the study. Overall, positive urine cultures were identified in 16.9% of cats with CKD, 13.2% of cats with DM, 21.7% of cats with HT, and 4.9% of cats with clinical signs of LUTD. Decreasing urine specific gravity was not associated with positive urine culture when controlled for disease but pyuria, bacteriuria, and hematuria were all associated with positive urine culture outcome. Persians, females, increasing age, and decreasing body weight were all associated with positive urine culture outcome. CONCLUSIONS: Performing a urine culture sample based solely on the presence of isosthenuria does not seem warranted. Further studies are warranted to help identify host predisposing factors for urinary bacterial colonization in cats with these diseases.
Companion NotesRetrospective report evaluating urine specific gravity and urine sediment as risk factors for urinary tract infections in cats
Study design - introduction on urinary tract infections (UTIs) in the cat - implicated organisms include bacteria, fungi, mycoplasma and viruses - several common metabolic diseases affect old cats - these include the following: - chronic kidney disease (CKD) - diabetes mellitus (DM) - hyperthyroidism (HT) - these may result in a higher incidence of bacterial UTIs in older cats - they affect bladder voiding patterns - they affect urine characteristics including specific gravity (SG) - isosthenuria might be 1 reason UTIs more common in older cats - they affect the immune responses - in 2 studies on lower urinary tract disease (LUTD) - bacterial UTIs are rare in young cats with signs of LUTD (hematuria, pollakiuria and dysuria) - in 1 recent retrospective study of urine cultures in 224 cats - positive urine cultures in 22% of cats with chronic kidney disease - positive urine cultures in 12% of cats with diabetes mellitus - increased UTIs associated with decreasing specific gravity (< 1.020) - positive urine cultures in 12% of cats with hyperthyroidism - in 1 report, UTIs common in diabetic cats regardless of degree of diabetic control - multivariate logistic regression, USG not associated with urine culture outcome - in author’s laboratory, urine is automatically submitted for culture if USG is < 1.015 - even with an inactive urine sediment - study sample: cats seen at Davis from 01/95-12/02 - 472 urine samples from 410 cats obtained by cystocentesis - 344 cats had CKD - 121 had DM - 46 had uncontrolled HT - 103 had signs of LUTD and a USG > 1.025 - cats with stranguria, hematuria, pollakiuria, dysuria, or combinations - procedure: records retrospectively reviewed
Results - decreasing urine SG not associated with positive urine culture - when controlled for disease - positive urine cultures identified in the following: - 16.9 % of cats with CKD - 13.2% of cats with DM - 21.7% of cats with HT - 4.9% of cats with clinical signs of LUTD - the following were associated with positive urine cultures: - Persian cat (irrespective of disease type) - Prevalence Odds ratio (POR): 3.57; 95% CI: 1.25-10.24 (p = 0.018) - female gender: OR: 3.53; 95% CI 2.16-5.76 (p < 0.001) - increasing age: - OR: 1.06 for each 1 year increase in age; 95% CI 1.002-1.12 (p = .042) - mean age: 10.4 years of age - pyuria - bacteriuria - hematuria - decreasing body weight - no significant association found between urine pH and positive culture - irrespective of disease type - 85% of all isolates were susceptible to the following: - amoxicillin/clavulanic acid - enrofloxacin - trimethoprim sulfa - cephalexin - ampicillin - multi-drug resistance (each susceptible to at least 1 common oral antibiotic) - 3 isolates of Enterococcus spp - 1 isolate of E coli, Enterobacter spp and Pseudomonas spp - among cats with positive urine cultures - 4 cats with CKD had lower urinary tract signs - 6 cats with DM had lower urinary tract signs - 2 cats with HT had lower urinary tract signs - isolates included the following: - Escherichia coli, 60 isolates from 54 cultures - not isolated from any cats presenting for LUTD - Enterococcus spp, 14 - Staphyloccocus spp, 8 isolates from 7 cultures - Streptococcus spp, 6
“Based on the urine cultures we evaluated, no association was found between decreasing USG and positive urine culture outcome; therefore, culturing the urine based solely on the presence of isosthenuria does not seem warranted.”
|
 |
|
| URL: http://www.vin.com/Members/Journals/Journal.plx?AID=1566814 | Document ID: 3768114 |
