the top number can fluctuate higher and its no big deal...we carry more weight and muscle than humans do so its my understanding that its normal for the top number to be higher the larger than human you are, the bottom number is importnat tha it be close to 80 as possible ..when that gets high you are heading for trouble..87's ok though...90's and above is a problem, though it can usually be handled with sodium reduction and otc duretics..