Bacteriuria in dogs with Cushing's: should it be treated?

Question

11-year-old Miniature Poodle with pituitary-dependent hyperadrenocorticism well controlled on trilostane. On a routine recheck, cystocentesis urine culture grows E. coli (>10,000 CFU/mL). There is no pollakiuria, dysuria or haematuria; it is afebrile and renal function is stable.

What is the most appropriate approach?

chevron_right Show answer and explanation

A. Treat for 4 weeks, because Cushing's makes any infection complicated

ISCAID 2019 abandoned the concept of 'complicated infection' due to comorbidity: there is no clinical infection to treat and long courses only select for resistance.

B. Always treat, because the patient is immunosuppressed

In dogs with Cushing's or diabetes, treating subclinical bacteriuria has not been shown to prevent clinical infections or pyelonephritis, and bacteriuria usually recurs.

C. Perform monthly cultures and treat every positive result

ISCAID advises against routine culture screening in patients without signs: it generates unnecessary treatment.

D. Do not treat the subclinical bacteriuria and monitor for lower urinary tract signs or pyelonephritis

Correct. Without clinical signs it is subclinical bacteriuria, which generally is not treated even with an endocrinopathy. Remember that endogenous corticosteroids may blunt pyuria and signs: assess fever, worsening polyuria or azotaemia.

lightbulb Key takeaway

In Cushing's and diabetes, bacteriuria is common and often silent. Treat only if there are lower urinary tract signs, suspected pyelonephritis or before certain urological procedures; do not chase positive cultures.

References: Weese JS et al. ISCAID guidelines for the diagnosis and management of bacterial urinary tract infections in dogs and cats (2019)

What is the most appropriate approach?

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