Page 734 - Small Animal Internal Medicine, 6th Edition

706 PART V Urinary Tract Disorders

though. A persistent infection implies the bacterial cultures had perineal urethrostomies. Choosing what, if any, antimi-
remain positive with the same organism during antimicro- crobial treatment for dogs or cats with subclinical bacteriuria
VetBooks.ir bial treatment. In this case, the organism has not been is not always clear (see later).
eradicated, even transiently, despite administration of the
Physical Examination Findings
appropriate urinary antimicrobial agent. Persistent infec-
tions imply severe abrogation of local host defenses or that The physical examination in dogs and cats with a simple
the organism is highly resistant to the administered antimi- uncomplicated bacterial cystitis is usually unremarkable.
crobial drug. Animals that present with recurrent UTI The bladder may be small and thickened, in some cases,
should have a thorough diagnostic evaluation (see later) to because of persistent inflammation and pollakiuria; caudal
search for underlying predisposing diseases. See Table 42.2 abdominal discomfort may be present in some patients. On
for a list of disorders and diagnostic considerations for rectal examination, the urethra may be prominent or more
animals with various forms of recurrent bacterial cystitis. severely thickened in cases in which urethral neoplasia or
Subclinical bacteriuria is a term used in human medicine proliferative urethritis (Video 42.1) is present. Urethral
to describe the presence of bacteria in the urine, as deter- stones may also be palpable, if present. Rarely, in more com-
mined by a positive bacterial culture, in the absence of LUTS. plicated cases, a large bladder is palpated in patients with
This has generally been referred to as subclinical UTI in the secondary urethral obstruction caused by neoplasia, usually
veterinary literature. Subtle signs of bacterial cystitis may be transitional cell carcinoma (TCC), proliferative urethritis, or
difficult to discern in small animals. Subclinical bacteriuria urethrolith. In females, the vulva should be examined to be
has been variably reported in dogs and cats with prevalence certain no evidence of a recessed vulva and/or perivulvar
rates in cats reported from 0.9% to 28.8%, and in one study pyoderma is present (Fig. 42.3). Similarly, the prepuce should
evaluating 101 healthy adult dogs, it was 8.9%. Cats were be examined for discharge, foreign bodies, or mass lesions.
oftentimes noted to be older and female. Subclinical bacte-
riuria is also anecdotally reported more often in animals with Diagnosis
underlying endocrinopathies, kidney disease, or micturition For simple sporadic UTI, a quantitative aerobic bacterial
disorders; in dogs and cats treated with glucocorticoids or urine culture from urine obtained by cystocentesis is indi-
immunosuppressive agents; or in those animals that have cated, followed by identification and susceptibility testing of

TABLE 42.2
Recurrent Infections

DIFFERENTIALS DIAGNOSES DIAGNOSTICS TO CONSIDER
Relapsing Clinical and microbiologic Urolithiasis Abdominal radiographs
cure of bacterial cystitis with Bladder polyps Contrast cystourethrograms
subsequent recurrence of Cystic neoplasia Abdominal ultrasound
disease. Deep seated bladder infections CBC
Pyelonephritis Serum biochemical panel
Chronic prostatitis Cystoscopy with biopsy
Altered mucosal immune responses
Persistent Continued presence of the Immunocompromised Radiographs
same bacterial strain in Cystic neoplasia Abdominal ultrasound
urine despite clinical cure Encrusting cystitis CBC
Severe micturition abnormalities Serum biochemistry
Altered mucosal immune responses
Reinfection Isolation of a different Hooded vulva Check external confirmation
microorganism after Cystic diverticulum CBC, serum biochemical panel
apparent resolution of a Ectopic ureter Abdominal ultrasound
previous infection Urinary incontinence (USMI or anatomic) Contrast cystourethrogram
Ureterocele Cystoscopy
Immunosuppression
Refractory Lack of clinical and Poor owner compliance Review dosing and compliance
microbiologic response to In appropriate drug or dosing regimen Radiographs
treatment Undetected antimicrobial resistance Abdominal ultrasound
Inability of antimicrobial(s) to penetrate the Cystoscopy
site of infection
Adapted from ISACID guidelines for the diagnosis and management of bacterial UTI in dogs and cats, Weese, et al., submitted, 2017.