UTI Flashcards
Significance and Incidence of UTIs in Dogs
Represent 5-17% of all canine admissions
Predispositions: females > males (length of urethra)
Physical defect causing incontinence (e.g ectopic ureters, “spay incontinence”/ urethral sphincter mechanism incompetence)
Urethral catheterisation!!!!! (damage to the mucosa, poor technique, “climbing frame” for bacteria)
Immunocompromise (hyperadrenocorticism, systemic disease, age-related)
Polydipsia/polyuria
Urolithiasis
Prostatitis (entire males)
Where do bacteria involved in UTIs normally come from
Normal gut or skin flora
All bar streptococcus commonly exhibit antimicrobial resistance
Clinical signs of lower UTI
May be none (“asymptomatic bacteriuria”; “subclinical UTI”)
Straining to urinate/difficulty urinating/painful urination/urinating in strange places/increased frequency of urination (pollakiuria, dysuria, stranguria etc)
Urine scalding (often a clue to incontinence as possible underlying issue)
Bloody/discoloured urine +/ or smelly urine (haematuria/pyuria)
Bladder may be painful to palpate/thickened but often empty
Abdominal pain
Licking/excess cleaning around vulva/prepuce
Use of urinalysis to treat/diagnose UTI
Collection via cystocentesis if possible
challenging when many UTI cases have an empty bladder
Catheter or free catch samples will be contaminated with environmental/external genital tract bacteria
Dipstick:
blood, protein, alkaline pH (but not always)
USG: this could be anything
if poorly concentrated urine consider underlying causes of polyuria/polydipsia
Urine sediment exam in UTI treatment/diagnosis
You MUST do a sediment exam
Air-dried stain
Centrifuge (or wait 20 minutes for sediment to settle)
Gram or methlyene blue stain
Pyuria
Large numbers of WBC’s (>5 per 40x field) indicate inflammation
Bacteriuria
Presence of bacteria indicates infection (contamination)
Use of urine culture for treatment/diagnosis of UTI
Definitive diagnosis
Prior to treatment
at least collect sample first!
Storage and transport of sample
Sterile container without additives
Commercially available kits
Refrigeration up to 6hrs
Blood or MacConkey’s agar
Antimicrobial sensitivity testing (the bacteria involved frequently display resistance)
How to deal with recurrent UTIs
This is very common
Failure of therapy:
incorrect treatment?
discontinued too early?
antibiotic resistance?
Prevalence of antibiotic resistance varies with place and time
Re-infection/persistent infection
usually indicates an underlying problem
you need to manage the UTI and the cause
is your patient immune suppressed?
could the dog have Cushing’s disease?
is the dog incontinent (ectopic ureters? USMI? (urethral sphincter mechanism incontinence)
Involvement of the upper urinary tract?
pyelonephritis – difficult to eliminate bacteria from this site
MUST do C&S - don’t persist with bad therapy
How should a UTI case be treated with antimicrobials
7-10 days for uncomplicated UTI’s (first occurrence)
Clinical response within 48 hrs – however full course must be finished (or significant relapse risk)
Complicated cases (pyelonephritis, prostatitis, recurring) 2-4 weeks (poor kidney concentration of drugs – flushed through)
Complicated cases: C&S at end of course should be negative
things to consider for antibiotic treatment of UTIs
Lab turnaround time? Owner finances?
Empirical therapy may be necessary
You must pick something that is likely to work against the bacteria you think are in there!
Which antibiotic to use for cystitis/ struvite urolithiasis (dogs)
amoxicillin/clavulanate or trimethoprim/sulfadiazine. (7-10 days)
Which antibiotic to use for UTI with prostatitis
: fluoroquinolones or trimethoprim/sulfadiazine.
Which antibiotic to use for pyelonephrits
trimethoprim/sulfadiazine or amoxicillin/clavulanate
