Antimicrobial therapy for urinary tract syndromes

The diagnosis and treatment of most cases of uncomplicated urinary tract infection (UTI) in dogs is straightforward and antimicrobial treatment is usually effective. However, some clinical cases are complicated by recurrence and the emergence of multi drug resistant (MDR) infections. Bacterial UTIs are a rare cause of lower urinary tract disease in cats. To minimize the emergence of MDR infection and to rationalize antimicrobial usage in the treatment of UTIs, guidelines have been developed (2011) and updated (2016). First line antibiotics for bacterial UTIs include amoxicillin and sulphonamde-trimethaprim. The current recommendation for treatment duration is 7 days but many clinicians believe shorter durations of treatment is likely to be effective.

A complicated UTI is an infection that occurs in a patient with a predisposing anatomic or functional abnormality. Recurrent UTIs, defined as three or more UTIs over 12 months, is also considered a complicated infection While some predisposing factors are easily identified (eg cystic calculi), predisposing factors cannot always be identified.

In small animals, the presence of positive urine cultures in patients without clinical signs of urinary tract disease is termed subclinical bacteriuria (SB). Many studies have identified SB in dogs with endocrinopathies, obesity, long term immunosuppression and spinal cord disease and in cats with CKD, hyperthyroidism and diabetes mellitus.

There are few studies on the long term outcomes associated with SB in dogs and cats. SB in cats is not significantly associated with creatinine concentration or with diabetic control. In short term studies, untreated SB in healthy adult dogs is not associated with development of clinical signs. In long term studies in non azotaemic, older cats, untreated SB was not adversely associated with survival.

Recording from 30.01.2019