Final answer:
To evaluate kidney function, the vet would run blood tests to measure the creatinine and blood urea nitrogen (BUN) values, which are elevated when the kidneys are not functioning properly.
Step-by-step explanation:
The vet is concerned about your dog's kidneys possibly failing, so they would run a blood test and look at the creatinine and blood urea nitrogen (BUN) values. These are important markers of kidney function and are typically elevated when the kidneys are not functioning properly.
Additionally, proteinuria (abnormal levels of protein in the urine) and hematuria (blood in the urine) may be indications of kidney issues, which are sometimes identified through urinalysis. It is the creatinine and BUN levels in the blood test that reflect the kidneys' ability to filter and eliminate waste products, with higher levels indicating compromised kidney function.