I was reading the "is my lab a runt" thread by robeec. My question is related but a little different. My boy is 65 lbs at 9 months and I am wondering what kind of growth rate labs have after 9 months. He is in great shape, and I am planning on keeping him that way. Think he'll hit 80lbs?
Your question is quite understandable and one that probably most owners of Lab puppies wonder. Hundreds (maybe thousands?) have asked the same question on the previous 6-10 JL forums.
BUT, although one might think there is a curve of growth typical for the Lab, while that may often be be true for those breeds with smaller numbers, for Labs -- with over 4X the AKC #s as the 3 next most popular breeds combined --- there is NO one growth rate.
BECAUSE there are so MANY Labs, there are thousands of breed lines. Within most breed lines, there'll be less variability. BUT between different breed lines -- and with all the BYB breeders -- there can be ENORMOUS variation in rates of growth and final adult weight at 24 months.
My Puff's rate of growth (YF, AKC, field line, 63 lbs., dob: 8-'01) was exactly the same as a friend's Lab, born the same day, which now weighs twice Puff's weight (YM, BYB, 130 lbs., dob: 8-'01).
FWIW, for purposes of your comparison, here's the rate of growth for my Puff:
Weiight at 63 days (9 weeks) -- 6 lbs.
Weight at 115 days (16.4 weeks) -- 18 lbs -- 3X the weight at 9 wks.
Weight at 165 days (23.7 wks) = 36 lbs.-- 2X the weight at 115 days.
Weight at 300 days (42.9 wks) = 54 lbs. (3X the weight at 114 days; 1.5X the weight at 165 days).
If you plot out this curve on a graph (age = X-horizontal, y = weight, vertical) you can can also plot out YOUR Lab's rate of growth and compare your Lab's rate of growth with Puff's. Then you can fairly closely estimate the final weight fairly accurately.
Puff [YF, AKC field line (from competing HT/FT breeder) 62 lbs, dob: 8-'01]