Ammonia levels in urine could signify chronic kidney disease
Dogs with low UACR were more likely to die of renal failure.
A new study from North Carolina State University has suggested that ammonia levels in urine could serve as a marker for chronic kidney disease in dogs.
Researchers believe that dogs with a lower urine ammonia-to-creatinine ratio (UACR) could be experiencing a faster progression of kidney disease and higher fatality rates.
For humans, chronic kidney disease is linked to an inability to excrete acids like ammonia through urine. This can lead to metabolic acidosis, which is a potentially life-threatening build-up of acid in the body.
However, researchers felt there was not enough research into the link between reduced ammonia excretion and accelerated kidney disease in dogs.
The team enrolled 50 dogs (22 female, 28 male) that were being seen for management or monitoring of International Renal Interest Society (IRIS) stage 2-4 chronic kidney disease. Each dog underwent initial blood and urine sampling to establish baselines and were seen four more times over the next 12 months.
Researchers concluded that dogs which had a UACR below 2.0 at enrolment were three times more likely to die of renal failure. They also had more rapid disease progression and experienced shorter survival times than dogs with higher UACR values.
This could mean that UACR could be used as an earlier marker of acid dysregulation than more traditional measures, including serum bicarbonate concentrations.
In the study, dogs had normal serum bicarbonate concentrations, but abnormalities in UACR levels. Altered urinary ammonia excretion could be more noticeable than changes detected in blood tests.
Autumn Harris, associate professor of nephrology-urology at NC State and first author of the study, said: “These findings indicate that UACR might serve as a clinically useful and non-invasive biomarker to identify dogs at risk of progression of their kidney disease who might benefit from early, targeted alkaline therapeutic intervention.
“Additionally, UACR could be used to help determine the prognosis for dogs with chronic kidney disease, allowing for interventions that could improve quality of life in these animals.”
The full study can be found in the Journal of Veterinary Internal Medicine.
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