Effects of the use of silver-coated urinary catheters on the incidence of catheter-associated bacteriuria and urinary tract infection in dogs

Abstract

OBJECTIVE To determine the effects of silver-coated versus standard silicone urinary catheters on the incidence of catheter-associated bacteriuria (CAB) and catheter-associated urinary tract infection (CAUTI) in dogs. DESIGN Randomized controlled clinical trial. ANIMALS 36 dogs requiring urinary bladder catheterization for ≥ 24 hours. PROCEDURES Dogs were randomly assigned to receive a silver-coated or non–silver-coated (control) silicone Foley catheter. Urine samples for cytologic examination and bacterial culture were collected at the time of catheter insertion and daily until catheters were removed (≥ 24 hours to 7 days later). Results were compared between groups. RESULTS No significant differences were identified between catheter groups in the incidence of CAB or CAUTI. Although the median time to development of cytologically detected bacteriuria, culture-detected bacteriuria, and CAUTI did not differ significantly between groups, median time to CAB development (either method) was significantly longer for dogs that received a control catheter rather than a silver-coated catheter. For both types of catheters combined, older age was a significant predictor of culture-detected bacteriuria, and longer duration of catheterization was a significant predictor of culture-detected bacteriuria and overall CAB. CONCLUSIONS AND CLINICAL RELEVANCE Silver-coated urinary catheters provided no clinical benefit over standard urinary catheters for the dogs of this study and were associated with earlier development of CAB but not CAUTI. A larger prospective study is required to definitively determine whether the use of silver-coated urinary catheters should or should not be considered to reduce the risk of CAB or CAUTI in dogs.

Urinary Catheter Coating Modifications: The Race against Catheter-Associated Infections

“…Another randomized study of 36 dogs was conducted where half were given a silver-coated catheter and the other half given an uncoated catheter. No statistical difference in the incidence of CAUTI was found, but the mean time to bacteriuria was shorter for the silver-coated group [84].…”

“…Silver ions are the most popular clinically tested and available coating for urinary catheters yet the effectiveness of them is still debatable due to vast differences in outcomes in vitro, in animal models and in clinical trials studies [34,51,[72][73][74][75][76][77][78][79][80][81][82][83][84][85][86]. The mechanisms by which silver is toxic to bacteria include disruption of the membrane, proteins, and by inducing oxidative stress through the release of silver ions into the bladder [15].…”

A comparative study of experimental urinary catheters containing silver and zinc for biofilm inhibition

“…28 However, an in vivo animal test in dogs of seven days found that there was no clinical benefit for these catheters over standard non antimicrobial catheters. 29…”

Three‐dimensional bladder ultrasound for estimation of urine volume in dogs compared with traditional 2‐dimensional ultrasound methods

“…[3][4][5][6] In people, the daily risk of bacteriuria with an indwelling urinary catheter is 3% to 10%, 7,8 and incidence of catheter-associated UTI among hospitalized dogs has been reported to be 10% to 19%. 6,[9][10][11] These observations highlight the need for alternative methods to measure UBV other than urinary catheterization.…”

“…In dogs, formulations derived from 2-dimensional (2D) ultrasound measurements have provided acceptable estimates of UBV and for calculating URV to assess UOP. 1,[8][9][10][11][12][13] Formulas derived from the human medical literature have inconsistencies associated with variations in bladder shape and size. 2,[12][13][14][15] Most recently, use of a simple formula of length (L) × width (W) × height (H) × 0.52 has provided the best estimation of bladder volume in people using 2D ultrasound B-mode images compared to other formulas.…”