However, when combined with other tests of kidney function, an elevated BUN can alert the doctor to a potential problem with the kidneys. Therefore, an elevated BUN by itself may not be clinically meaningful. As mentioned above, mild elevations on a scale of 10 to 20 units can be normal for your dog if other testing of kidney function is also normal. With kidney disease, the BUN begins to slowly elevate. Unfortunately, it’s also affected by other factors such as intestinal bleeding and dietary protein levels. Kidney function BUNīUN is a common test of kidney function. Let’s take a look at some commonly performed tests and what they mean. However, re-do the test every few months, especially if you have an older dog since kidney disease is more common in senior animals. If they weren’t, it’s likely your dog’s BUN value of 40 is nothing to worry about. Look at other tests of kidney function (creatinine, phosphorus, complete urinalysis, etc.) and see if those were abnormal. If he has never had this test done before, repeat it in one to two weeks and compare the value to the current one. If your dog has always had BUN values close to 40, it’s probably safe to say this is another normal test. How do you determine if this is normal, or a sign of potentially serious kidney disease? This is where the vet’s medical training and experience comes in to determine if it was normal for your dog (in which case it’s nothing to worry about) or abnormal.įirst, look at BUN values from prior tests, if available. Let’s suppose your dog has a BUN value of 40, which is outside the normal range on the high end. However, 5% of normal dogs will have a lab value less than 10 and 5% a value greater than 30. This means 90% of normal dogs will have a BUN value anywhere from 10 to 30. Normal values for most labs are 10 to 30. As an example, let’s look at the BUN test (blood urea nitrogen), commonly used to determine kidney disease.

Urea nitrogen bun normal range