Glad Beau is still doing well! I never saw this post before but I think I can write a little spiel on renal function now as I've just learned it in school.
The values for Beau don't seem to be TOO too off. We also look at how the dog is doing clinically. It never hurts to screen him every so often.
With renal function, we look at two very important parameters. These two parameters are:
BUN - blood urea nitrogen and
creatinine. In our body (and our pugs), we have something called the urea cycle. Our liver produces urea as a a waste product from digestion of proteins in our body. Creatinine is a breakdown product of creatinine-phosphate in muscle. Again, our body filters out creatinine through the kidneys.
When our kidneys don't work properly, there is that extra BUN and creatinine that just can't get filtered out so when we take blood from our dogs, we see that excess. An increased BUN & creatinine is known as
azotemia.
Azotemia is a pretty good sign of renal failure and there are THREE categories
1) Pre-renal - this is usually due to something like dehydration
2) Renal - something is happening WITHIN the kidneys
3) Post-renal - something is happening AFTER the kidneys - so this can be at the level of the urinary tract (ie: urinary obstruction)
When we look at something like chronic kidney disease (aka CKD), we usually see azotemia, a low USG (urine specific gravity), and we also see clinical signs. Usually when we see azotemia in a biochemistry profile (the blood test your vet probably did), we move onto other other things immediately.
The first thing we do is collect a urine sample to see if the kidneys are working properly. What we DON'T want is something called an "isosthenuria". Kidneys are smart and when we are dehydrated, they really try to retain as much water in the body as they can and our urine comes out very concentrated. If we drink a lot of water, our urine is a lot more dilute. For animals that are dehydrated but have a urine specific gravity of between 1.008 - 1.0012, we call that isosthenuria. This means that they kidneys aren't able to concentrate the urine.
Another thing we want to do is a UPC (urine protein/creatinine ratio) to see how bad the kidney disease is. A high UPC means that there is more protein in the urine, which is a risk factor that promotes to progression of CKD. Other tests with urine that we'd like to do is a urine culture to make sure there's no bacteria and an underlying pyelonephritis.
Higher levels of diagnostics are available such as radiographs/x-rays or ultrasound. These can show us the size of the kidneys, any irregularities, stones, obstruction, etc.
Hopefully, this clears up some stuff about the kidneys. Again, with an older dog, it never hurts to screen ever 6 months to 1 year to see how your dog is doing. However, clinical signs are also very important so if you notice any change in behaviour, it's always important to take them to your local veterinarian right away. It is definitely hard as an owner to know what's "too high" and what's "too low" but the veterinarian (after many hours and hours of renal lectures - not complaining here...
) are usually pretty good at handling these kidney cases or referring them to specialists who solely focus on urology/nephrology stuff (ie: the prof I worked for this year). As an owner though, it is awesome you are so proactive about these situations.
Hope Beau continues to do well - he seems like a very sweet dog!
