Evaluation of urinary neutrophil gelatinase-associated lipocalin to detect renal tubular damage in dogs with stable myxomatous mitral valve disease

Neutrophil Gelatinase-Associated Lipocalin (NGAL) as a Biomarker of Acute Kidney Injury (AKI) in Dogs with Congestive Heart Failure (CHF) Due to Myxomatous Mitral Valve Disease (MMVD)

Dogs with acute congestive heart failure (CHF) can develop acute kidney injury (AKI); the prevalence of this condition has not been defined. This study aimed to assess the occurrence of AKI (increase in serum creatinine (sCr) ≥ 0.3 mg/dL) within 48 h from admission in dogs with myxomatous mitral valve disease (MMVD) with acute CHF, and the role of urinary neutrophil gelatinase-associated lipocalin (uNGAL) as a predictive marker of AKI. This was a multicentric, prospective observational study. Thirty dogs were included. The types and dosages of the diuretics administered, as well as the serum and urinary chemistry, including uNGAL and uNGAL, to the urinary creatinine ratio (uNGALC), were determined at admission (T0) and after 24 (T24) and 48 (T48) hours of hospitalization. Nineteen dogs developed AKI. We found no statistically significant differences in sCr, uNGAL, uNGALC, diuretic dosage, or hours of hospitalization between dogs that developed AKI and those that did not. The urinary NGAL and uNGALC values were not statistically significantly different at any time point, while the sCr was higher at T24 and T48 than T0. Our findings suggest that AKI in MMVD dogs with CHF is primarily functional, driven by effective decongestion rather than severe tubular damage, with the benefits of decongestion outweighing transient increases in sCr.

Renal Biomarkers in Companion Animals-A Review

Recent advancements in molecular biology have led to the discovery of potential biomarkers for the diagnosis of acute kidney disease (AKD) and chronic kidney disease (CKD). The use of multiple biomarkers in the diagnosis of kidney disease has the potential to enhance both specificity and sensitivity, enabling early detection and intervention that could ultimately reduce morbidity and mortality rates. This review provides an overview of studies on urine and blood biomarkers and examines their utility and significance in various clinical settings. Further and continuous research is needed to support the application of these biomarkers in clinical practice to facilitate early diagnosis, guidance for different interventions, and the monitoring of disease progression.

Association between echocardiographic indexes and urinary Neutrophil Gelatinase-Associated Lipocalin (uNGAL) in dogs with myxomatous mitral valve disease

Neutrophil gelatinase-associated lipocalin (NGAL) is a biomarker of tubular damage, and its elevation has been described in human and canine cardiorenal syndrome. The aim was to evaluate the association between echocardiographic indexes and urine NGAL (uNGAL) and uNGAL normalized to urine creatinine (uNGALC) in dogs with MMVD. This is a multicentric prospective cross-sectional study. A total of 77 dogs with MMVD at different ACVIM stages were included. All dogs underwent echocardiography, serum chemistry, and urinalysis. Echocardiographic data analyzed were shortening fraction (SF), left ventricular diastolic (LVIDDn) and systolic (LVIDSn) diameters normalized for body weight, left atrium to aortic root ratio (LA/Ao), maximal (LAVMax) and minimal (LAVMin) left atrial volumes, LA stroke volume (LASV), early diastolic mitral peak velocity (EVmax), EVmax to tissue Doppler E' wave (E/E'), aortic (VTIAo) and mitralic (VTIMit) velocity time integrals and their ratio (VTIMit/VTIAo), and tricuspid regurgitation velocity (TRVmax). In the univariate analysis LASV, TRVmax, LAVMax, LVIDDn, and VTIMit/VTIAo were independent predictors of increased uNGAL and uNGALC; however, only LASV [(OR: 1.96, 95% CI: 1.16 to 3.31) P = 0.01 for NGAL, and (OR: 2.79, 95% CI: 1.50 to 5.17) P < 0.001 for NGALC] and TRVmax [(OR: 1.73, 95% CI: 1.20-2.51) P = 0.002 for NGAL, and (OR: 1.50, 95% CI: 10.07-2.10) P = 0.015 for NGALC] remained statistically significant in the multivariable analysis. Based on our results, LASV and TRVmax are associated with increased uNGAL and uNGALC. These parameters might detect dogs with MMVD at higher risk of developing kidney damage.

Use of serum osmolality to identify heart disease stage in dogs and relationship to mathematical chloride correction

BACKGROUND

Heart failure-associated hypochloremia can be depletional from diuretics or dilutional from water retention. Serum osmolality reflects water balance but has not been evaluated in dogs with heart disease.

HYPOTHESIS

To determine if serum osmolality is related to heart disease stage and amount of mathematical correction of serum chloride (Cl- ) concentrations in healthy dogs and dogs with myxomatous mitral valve degeneration (MMVD).

ANIMALS

Seventy-seven dogs (20 healthy, 25 Stage B MMVD, 32 Stage C/D MMVD).

METHODS

Serum Cl- concentrations were mathematically corrected. Osmolality was calculated (calOsm) and directly measured by freezing point depression (dmOsm) and compared by Bland-Altman analysis. Biochemical variables and osmolality were compared among healthy, Stage B, and Stage C/D dogs. Correlations were explored between osmolality and biochemical variables. Median and range are presented. P < .05 was considered significant.

RESULTS

The calOsm was different among groups (P = .003), with Stage B (310 mOsm/kg; 306, 316) and C/D dogs (312 mOsm/kg; 308, 319) having higher calOsm than healthy dogs (305 mOsm/kg; 302, 308). Osmolality methods were moderately correlated (P < .0001, rs  = .46) but with proportional bias and poor agreement. The amount of Cl- correction was negatively correlated with calOsm (P < .0001, rs  = -.78) and dmOsm (P = .004, rs  = -.33). Serum bicarbonate concentration was negatively correlated with Cl- (P < .0001, rs  = -.67).

CONCLUSIONS AND CLINICAL IMPORTANCE

Dogs with Stage B and Stage C/D heart disease had higher calOsm than healthy dogs. Osmolality was inversely related to the amount of Cl- correction, which supports its use in assessing relative body water content. Poor agreement between calOsm and dmOsm prevents methodological interchange.