I wish I was that organized (excel etc.). I use a small yellow pad and make all my notes for each litter in it. Then I file it away until the next litter. I have to drag them all out each time to compare my notes, etc.
I just looked at them last night. My smallest puppy at birth was 3.8 oz., and she is now an 8 lb. dog! Go figure. I also had a 6.2 oz. puppy that is now 6 lbs.
I keep trying to treat this as an exact science, and it just isn't.
