Retrospective evaluation of C-reactive protein for discriminating between lower urinary tract infections and acute pyelonephritis in dogs
Francesca Fidanzio, Greta Colombo, Kateryna Vasylyeva, Alessandro Tirolo, Maria Chiara Sabetti, Isabella Tirelli, Erika Monari, Andrea Corsini, Francesco DondiAbstract
Background
The role of C-reactive protein (CRP) in differentiating pyelonephritis from other types of urinary tract infection in dogs is not well defined.
Hypothesis/Objectives
Compare serum CRP concentrations at diagnosis in dogs with acute pyelonephritis (APy), acute prostatitis (APr), and bacterial cystitis (BC). Serum CRP concentration is hypothesized to be higher in APy and APr than in BC.
Animals
One hundred fifteen client-owned dogs were included: 56 with BC, 32 with APy, 23 with APr, and 4 with both APy and APr.
Methods
Retrospective observational study. Dogs with positive urine culture were included and divided into 3 groups (BC, APy, and APr), based on medical history. Dogs with comorbidities potentially affecting CRP concentrations and dogs with subclinical bacteriuria were excluded. Data were compared among groups, and the diagnostic accuracy of CRP was assessed post-hoc.
Results
Dogs with BC had lower median CRP (1.04 mg/dL; range, 0.08-7.21) than those with APy (23.65 ± 11.96 mg/dL; median difference [MD], 22.9 mg/dL; 95% CI, 18.2-26.5; P < .001) and APr (20.9 mg/dL; range, 5.93-55.97; MD, 19.9 mg/dL; 95% CI, 10.7-25.6; P < .001), whereas APy and APr did not differ (MD, −3.0 mg/dL; 95% CI, −10.6 to 4.4; P > .99). Serum CRP concentration had high discriminative ability to differentiate dogs with BC and APy, APr, or both (area under the curve [AUC], 0.99; 95% CI, 0.99-1).
Conclusions and clinical importance
Serum CRP concentration evaluated at diagnosis, when highly increased, may help differentiate BC from APy in dogs without concurrent inflammatory diseases.