There is only one way to REALLY know how big your puppy will get. If you got a purebred dog then hopefully you went to a reputable breeder, met the parents, and did your research regarding the breed specifics. Odds are you will have a good range within a few pounds and accurate height.
If you’re one of the many who adopted from a shelter, then let the guessing game begin! Our newest dog, Maya, was listed as an Australian Cattle Dog / mix. Turns out the shelter uses this classification as their catch-all. Speaking with friends and other volunteers from other shelters we’ve learned they are all pretty much guessing. So what do you do?
Well, first of all, as a puppy at say maybe 8-10 weeks (assuming you know the birth date), was your dog ‘big’, ‘medium’, or ‘small’? We expect Maya to be medium, but started having 2nd guesses until we met a Husky the same age, who was at least 30% bigger than her already.
We also learned of a general trick where you take their weight at 14 weeks (Maya was 18 lbs), double it (36 lbs), and then take half-again the original weight (18 divided by 2 = 9) and add it in (36+9 = 45). At the time of this writing, she’s gaining at about a pound a week, and came in at around 20 lbs for her 16-week checkup. We’ll update as time goes on to see if that formula works or not.
For additional reference, we took her to the vet twice since adoption for the wellness exams and booster shots. They weigh her each time, and this is what we recorded:
| Date | Age | Weight | Gain/Week |
| 10/19/2010 | 9.15 weeks | 7.9 lbs. | – |
| 11/4/2010 | 11.4 weeks | 11 lbs. 3 oz. | ~1 lb |
| 12/6/2010 | 16 weeks | 20 lbs | ~2lbs |
| 12/20/2010 | 18 weeks | 23.5 lbs | ~1.75 lbs |
| 12/27/2010 | 19 weeks | 25 lbs | 1.5 lbs |
| 1/3/2011 | 20 weeks | 28.6 lbs | 3.6 lbs1 |
| 1/12/2011 | 21.3 weeks | 29.8 lbs | ~1 lb |
| 1/17/2011 | 22 weeks | 31.8 lbs | ~2 lb |
| 1/24/2011 | 23 weeks | 33.4 lbs | ~2 lb |
| 1/31/2011 | 24 weeks | 35 lbs | ~1.5 lbs |
| 2/7/2011 | 25 weeks | 36.6 lbs | ~1.5 lbs2 |
| 2/14/2011 | 26 weeks | 37.6 lbs. | ~1 lb |
| 2/14/2011 | 26 weeks | 37.6 lbs. | ~1 lb |
| 2/21/2011 | 27 weeks | 40 lbs. | ~2.5 lbs3 |
| 2/28/2011 | 28 weeks | 40.2 lbs. | negligible |
| 3/28/2011 | 32 weeks | 42.6 lbs. | 0.5 lb. (for 4 weeks) |
| 4/11/2011 | 34 weeks | 42.6 lbs. | No Gain |
1 NOTE: Around (12/27 – 1/3) I increased her food to 2 cups twice a day. This is double what the manufacturer recommends, and about 50% more than what her vet had said. She just looked SO skinny I thought it couldn’t hurt. I’m now going to trim this back a bit to keep her under the 2 lbs/week rate.
Since 1/3/2011 I dropped her food to about 1 1/2 – 1 3/4 cups twice a day (half a cup less than she had previously been given but still more than recommended on the bag of Purina Puppy Chow.) and we learned that while staying with her beagle cousins for a few days she was eating so fast it was making her puke a couple times. You can see the results. Her weight gain definitely tapered off a bit.
Between 11.4 weeks and 16 weeks when she was seen at the vet’s office, her doctor commented that her growth rate and overall appearance were terrific. She, like most puppies, started as a bit of a butterball, but has been lengthening and ‘skinnying’ since. Technically, her ribs show just a bit but this is okay. It’s best to keep dogs on the lighter side during these formative years so as to not impede limb and joint growth. Running around ‘fat’ doesn’t help.
We’re feeding her twice a day at about 1 1/4 – 1 1/2 cups for 2.5-3 cups/day. As she is ‘treat motivated’ for training, she’s also getting a ton of snacks throughout the day.
2NOTE: For the past few weeks we’ve been giving Maya 1.5 cups of food twice a day. Just this past week we introduced the Topsy Turvy dog-treat toy by Kong. With it, she’s been getting another 1/2 cup of food a day.
3NOTE: Seems we saw a bit of a growth spurt for Maya this week. The bit of extra food from the Topsy-Turvy contributed some, but I suspect it’s mostly muscle. During this same week we walked Maya 6 out of 7 days for a total of 26 miles. (Well, we did 26 miles, but three of those walks (9 miles) were at the off-leash open-space. So while we walk straight, Maya is running, zigging, zagging, playing, etc. I’d suspect she does at least another 2 miles.)
(Creative Commons photo courtesy Caden Crawford, Flickr)
