Predicting Adult Weight

[Scott]

Hi all,

This is my first post; I haven't properly introduced myself yet. I'll have my puppy in a few weeks, and hopefully that will make me interesting enough to warrant an introduction.

I've seen a lot of posts regarding puppy weight and how that may relate to final adult weight. After the topic came up with my breeder, I wanted to investigate it a little more. I found this paper first. Using the labrador retriever data, you get this graph. You'll notice the number 61.95 on the graph and in the equation in the search box. From the paper, this is the maximum adult weight expected for the breed. Obviously this isn't of very much predictive value, but it does give you an idea of how the weight should change. It is also interesting to note the differences between the equation and the growth curve in the paper. The equation isn't very accurate until 13 weeks or so. (Note the paper is in kg instead of lbs)

I rearranged the equation to try and make it predictive. Using 16 weeks, the formula simplifies to: (current weight) + 1.2*(current weight). Again this is based on the expected growth and adult weight of a lab, so it will be off as the dog deviates. I've been working through a DK weight update thread, and it does a decent job. There are some instances where it is way off though.

I'm going through finals right now, but would like to try and improve the formula. I think if I pulled the data out of that thread by doodle type, some of the coefficients could be made more accurate. It has been a fun procrastination project so far.

I also wanted to note that it is very similar to the double 16 weeks weight + ~10 lbs rule of thumb of I've seen. Assuming your dog is 20-30 lbs at 16 weeks, you're just doubling it and adding 4-6 lbs this way.

Let me know what you all think. Is it worth following up on? If you have a standard labradoodle, does it seem accurate?

[Malenie Piscetelli]

What about Goldendoodle?

[Scott]

Since the paper didn't have data for golden retrievers, I left them out. That would be part of going through the other thread to get some more specific data.

[Lucy & AnnaBelle's Mom]

I read this the first time at 6am this morning and as I was shaking my head going "what?" I thought Dude, you have way too much time on your hands!  Good Luck though if it's what you enjoy!   You might want to get it done now though as when you get your puppy in a few weeks you won't have so much free time, lol

[Scott]

This is along the same lines of what I work on day to day. However, I didn't have to do much for this. The paper gives you the formula. I'm not sure how accurate some of the data is when applied to doodles. For instance, they say a lab reaches 99% of adult weight at 52.1 weeks, and 50% of adult weight at 18.6 weeks. Even if that is similar for standard size doodles, it is definitely different for mini doodles.

That's actually another point of the paper: given the time it takes to reach adult weight is so different, the transition from puppy food should occur at significantly different times.

In any case, I don't mind spending a little time on it. It is puppy selection week with the breeder and I was hoping it would be helpful. Besides, it isn't that big of a time sink and I thought others might find it helpful/interesting.

[Stephanie and Ragley]

Wow! Such a cool project to keep your mind busy! It would be cool to have a more accurate formula. Unfortunately for our dear doodles, from what I have experienced anyway, is that the mixing of the breeds does not spit out a generic body style/shape/build such as you would see with a pure labrador. You will see quite the variety of body shapes- some end up with more of a retriever build and thus are heavier, but not as tall and some end up with more of a poodle body and shoot "up" without much "out". Because of this, you can have a litter of puppies all around the same starting weight that end up being quite varied as adults. I have plugged Ragley's statistics into many online formula websites and gotten crazy results- I had one that I used that utilized puppy weight and it spit out an adult weight that was two pounds less than what she already weighed at 6 months haha. Also adding into this- when my puppy was little, when I wondered about adult size, it was actually more about height than it was about weight as I now can look back and see. There are a lot of dogs out there that Ragley plays with that are her weight (or more), but are at least a few (or more) inches shorter than she is. What I think would be a truly interesting formula is if there was one in which weight could be factored with height to produce an adult estimate. For instance, if you knew your puppy was 16 weeks old, 19" at the shoulder, and weighed 34 lbs- you could punch that in and get an estimate that he/she would be X" tall and Y lbs as an adult. 

Very cool, though!

[Debb, Lucy & Oscar]

I'm not seeing how an accurate formula to determine adult doodle weight would be very helpful for those who get puppies before 16 weeks old, if, in fact, they want it to help them in their puppy choice. So it really is kind of a crap shoot and you have to look at the puppy's parents for a weight range. With that said, it is an interesting endeavor just for the fun if it and I, for one, was very curious how big Oscar would get when he was a small puppy. He's a standard multi-gen Labradoodle and his breeder believed he'd get no bigger than 40lbs. He was the smallest male and as small as the smaller females in his litter. He's now about 20-1/2 mos. old and at his last weigh in he was just over 65lbs. We think he's pushing 70lbs now but need to weigh him to verify. The formula seems to be very accurate at least from the facts we have to date on Oscar. At 16 weeks he weighed 29.4lbs. Also, using the old formula he's right in the middle of the projected weight range: Estimated mature weight: 29.4 lbs. x 2 = 58.8 lbs. + 5-10 lbs = 63.8 - 68.8 lbs
Here's a weight progression discussion I started on Oscar last year:

http://www.doodlekisses.com/group/puppymadness/forum/topics/do-you-...

[Scott]

I agree that it is probably useless at such an early stage. My original hope was to find something helpful during selection. However, it seems there is too much volatility in weight when they're so young.

It's nice to see it worked fairly well for you. I'm also getting a standard multi-gen Labradoodle. I think that "doodle type" is the most applicable to the data from the study. This is my first dog, aside from the family dog growing up. There is a very good chance I'm just going overboard with everything.

[Nancy, Ned, Clancy, and Charlie]

 Because doodles are a mixed breed dog, a cut and dried formula is not going to work consistently like it might  for a pure breed dog with size standards and range expectations. Doodles range from mini to huge.  Small dogs reach physical maturity  at a much younger age than larger ones.  However, if you are a numbers guy - and it sounds like you are, perhaps you will find a new way to look at weights and apply them.  It would be very cool to have a more accurate prediction when you are choosing a puppy.