Is weight at adulthood more predictable if parents are similar in size?

[Wendy and Sophie]

Hello all.  We are considering F1 puppies from a couple of different breeders.  The first has large minis, where the dam is 90 lbs and the sire is 10 lbs.  They are predicting puppies at 30-40 lbs (they are 3 lbs at almost four weeks). We are also looking at standards with a different breeder, where the sire is 65 and dam is 55 lbs, and they are expected to be 55-65 lbs at adulthood.  I'm curious as to whether the second litter will be more predictable given that the parents are closer in weight to each other.  With the first litter, we are certainly open to a larger dog, but would not want a dog that's as large as the mom. The breeder thinks 30-40 will be the range, but I'm curious as to whether it's just less predictable with the big differential in the parents' weights.  The breeder has bred the sire before to a smaller dam and had puppies in the 20-35 lb range.

Thanks for any insights you can share! 

[Karen, Jasper and Jackdoodle]

First, a breeding between a 90 lb dog and a 10 lb dog is a very bad idea, in terms of possible structural problems in the puppies. So I would avoid that breeding completely, even if the breeder was being honest and telling you that there is absolutely no way that he/she can predict the adult size of the pups from parents of such extremely disparate sizes. Genetically, it is likely that they will be bigger than 30-40 lbs, maybe much bigger. I personally would avoid this breeder like the plague.

In the case of the second litter, the size predictability is much more likely and sounds much more accurate. But even there, it could be possible to get a dog who is considerably larger than either parent, depending on what generation the parents are and how far back the retriever ancestors are in the pedigree. If the parents are multigens or ALDs, the estimate should be pretty accurate. If they are F1s, more variation is likely. 

[F, Calla & Luca]

Exactly. The size of dogs may be gradually brought down, or up for that matter, but to breed such disparate size dogs is a recipe for trouble in my opinion.

[Stefan]

Agreed. 

[Wendy and Sophie]

Thanks so much, Karen. I'm glad I posed the question! This breeder has done several litters with the 10 lb poodle and a 77 lb golden. This is his first with the 90 lb golden. That's good to know!

Also, it's interesting because the second breeder said she has more weight disparity in her F1b litter (parents are 45 and 55 lbs.). Thanks again for your insights.

[Stella]

My F1 LD came from a small lab (60lb) mother and a small standard poodle (55lb) father. He grew into a lean 75lb dog!! My multi-gen x ALD was predicted to be 35-40lb, he is a skinny 50lb!! I don't know if I just have a knack for picking puppies that are going to be bigger than predicted, but I love large dogs so I was pleased they got bigger than predicted. But, it goes to show you can never be sure!

On a side note, why on earth would you breed a 90lb and 10lb dog together????

[Wendy and Sophie]

Thanks for your insights, Stella. I'm definitely skipping the 90lb/10lb litter, and will concentrate on the 55lb/65lb litter.  It's good to keep in mind that they may significantly exceed expected weight ranges!

[Rosemary (Ro) and Enzo]

Your second example sounds like Enzo' s parents. She is falling exactly where her Breeder projected...50-55 lbs. Tho, I suspect she will be closer to the lower number. She is 11 months and at 50 lbs.

[Diane, Baker & Oskar]

Baker's (F1) parents were 55-60# & he is 88# now (after losing some weight :)  Very tall & long with a big build.  When I mentioned his size to the breeder, she said there have been other large dogs due to the genetics of the sire.

Oskar's (double doodle) parents were 55# & 20# & he is 32#, predicted to be 40+#.

So....one of ours turned out much larger than predicted, the other smaller than predicted.   Just like kids :)

[Pam Thomas]

That had to be an interesting mating with the difference in size,lol

[Wendy and Sophie]

I was thinking that, too, Pam!

[Wendy and Sophie]

Another doodle kisses person  has a dog from this breeder and raves about him; and his facebook page is also full off raves.  her dog is from a 60lb/10lb mating though, so a bit less disparity.

[Lucy & AnnaBelle's Mom]

What you have to keep in mind Wendy is that just because someone (I don't know who this is so I'm not getting personal here) has a dog that they rave about doesn't mean that the breeder is a good one.  There are people here who rave about their puppy mill puppies which means they didn't come from a reputable breeder.   One must do their homework.