Escherichia coli pyometra induces transient glomerular and tubular dysfunction in dogs.

BACKGROUND

Pyometra in dogs has been associated with renal injury.

HYPOTHESIS

Examine pyometra-related nephropathy by evaluating novel renal biomarkers.

ANIMALS

Twenty-five dogs with Escherichia coli pyometra. Fourteen clinically healthy bitches of comparable age.

METHODS

Prospective study. Urinary biomarkers determined by immunoassays (uIgG, uCRP, uAlb, uRBP, uTXB2) or colorimetric test (uNAG) with results normalized to urine creatinine concentration. Nonparametric Mann-Whitney U-test and Wilcoxon's signed-rank test used to compare healthy dogs and dogs with pyometra, and dogs with pyometra at initial and follow-up examination.

RESULTS

Urinary biomarkers (median, range) significantly increased in dogs with pyometra (uIgG/Cr: 169.7 mg/g, 4.8-1052.9; uCRP/Cr: 0.260 mg/g, 0.006-3.030; uAlb/Cr: 89.5 mg/g, 8.8-832.7; uRBP/Cr: 1.66 mg/g, 0.05-21.44; uNAG/Cr: 5.8 U/g, 1.6-27.7; uTXB2 /Cr: 15.3 μg/g, 3.2-139.6) compared with healthy bitches (uIgG/Cr: 3.4 mg/g, 0.6-8.9; uCRP/Cr: below detection limit; uAlb/Cr: 17.5 mg/g, 1.3-166.3; uRBP/Cr: 0.13 mg/g, 0.02-0.44; uNAG/Cr: 2.4 U/g, 1.4-7.4; uTXB2 /Cr: 2.4 μg/g, 1.2-4.7) (P<.001). Six months after ovariohysterectomy, urinary biomarkers in pyometra group (uIgG/Cr: 4.7 mg/g, 1.5-99.8; uCRP/Cr: below detection limit; uAlb/Cr: 13.9 mg/g, 2.1-471.2; uRBP/Cr: 0.05 mg/g, 0.02-0.32; uNAG/Cr: 1.6 U/g, 0.9-3.3; uTXB2 /Cr: 3.3 μg/g, 1.0-6.9) were significantly lower than before surgery (P<.01), and not significantly different to those of healthy dogs (P>.05).

CONCLUSION AND CLINICAL IMPORTANCE

Pyometra-related renal dysfunction affects the nephron both at glomerular and proximal tubular level and is a transient process in most dogs with E. coli pyometra.