BUN levels?
it can point to a couple of things, including kidney disease, but often, like WhiteDove said, it's just dehydration (if you also had your creatinine level checked and that was normal, then it's most likely dehydration. If it's kidneys, the creatinine level would be high as well). Check with your doctor - and make sure you're drinking enough fluids.
(P.S. I know this because I've owned around 16 cats, and cats are NOTORIOUS for kidney disease when they get older. BUN and creatinine levels are the two indicators for kidney issues - but again, high BUN can also mean dehydration. So if creatinine is normal, then high BUN is most likely just dehydration)
Thank you for your informative responses! He is very responsive but I wanted to make sure we had no special considerations since he isn't knowledgeable.
i tested, am going to try the hydration route and re test