# Urinary NGAL as an Early Marker of Renal Dysfunction in Dogs with Heartworm Disease and Pulmonary Hypertension

## TL;DR

This study shows that urinary NGAL can detect early kidney damage in dogs with heartworm disease and pulmonary hypertension, even when standard tests appear normal.

## Contribution

The study demonstrates that uNGAL is a novel early biomarker for renal dysfunction in dogs with heartworm disease and PH.

## Key findings

- Dogs with PH had significantly higher uNGAL levels than those without PH.
- uNGAL levels were elevated despite normal creatinine and BUN values.
- uNGAL is a sensitive indicator of early kidney damage in these dogs.

## Abstract

Heartworm disease is a serious condition in dogs caused by the parasite Dirofilaria immitis. In advanced stages, it can lead to pulmonary hypertension (PH), a condition that affects both the lungs and heart. PH may also harm the kidneys, even before standard tests like creatinine or urea indicate any abnormalities. In this study, we examined a protein called urinary NGAL (uNGAL), which is released by kidney cells in response to injury, to determine whether it could help detect early kidney damage in dogs with heartworms. We found that dogs with PH had higher levels of uNGAL than dogs without PH, despite having normal results on standard kidney tests. These findings suggest that uNGAL may be a valuable tool for detecting early renal damage and improving disease monitoring in affected dogs.

Heartworm disease, caused by Dirofilaria immitis, often leads to pulmonary hypertension (PH), a serious cardiovascular complication in infected dogs. PH may impair renal function through hemodynamic and inflammatory mechanisms, even when traditional biomarkers such as serum creatinine and blood urea nitrogen (BUN) remain within normal ranges. This study aimed to assess urinary neutrophil gelatinase-associated lipocalin (uNGAL) levels in dogs naturally infected with D. immitis, with and without PH, to evaluate its potential as an early biomarker of renal dysfunction. Forty-two infected dogs were included and divided into two groups based on the presence (n = 14) or absence (n = 28) of PH, diagnosed via echocardiography. uNGAL concentrations were significantly higher in dogs with PH (mean 66.49 ± 6.67 ng/mL) compared to those without PH (mean 49.01 ± 14.48 ng/mL; p < 0.0001), despite normal creatinine and BUN values. No significant associations were found between uNGAL and sex, age, breed, or clinical signs. These findings suggest that uNGAL may serve as a sensitive biomarker of early renal impairment in dogs with heartworm disease and PH, even in the absence of overt azotemia, supporting its use in clinical evaluation and the monitoring of disease progression.