I assume it’s the same odds as with a coin toss. So 50% to the power of the number of puppies in the litter. So if 6 puppies in the litter 50% x 50% x 50% x 50% x 50% x 50%. So approx 1.5%. I’m happy to have my maths corrected. Also if you’re hoping for a puppy of a particular sex, remember the great Terry Pratchett who said, ‘The thing about million-to-one chances is that they’re always coming up.’
Ahhh. The lovely Terry Pratchett. A feral cat that used live on my land had litter after litter of female kittens and then suddenly had a litter with one male in it. It was the only male she ever had. Eventually, I did manage to tame her enough to handle her but by then she was too old to have any more kittens. I did tame all the kittens though and thoroughly enjoyed doing so.
If there's only one in the litter I'd say the chances are pretty good. WE had a dumped cat give birth in our backyard and when we trapped Mum and brought her and the four kittens inside the babies turned out to be all female. When I took them in to be Vetted the Vet said four of all the same sex was not unheard of but he'd have expected there to be at least one male. Maybe there was, they were 9 days old when we got them, if one died the mother would probably have removed it.
I visited someone with a litter of four girls a few weeks ago. Could have been choc or black and they were also all black! The breeder said, "What are the odds? I should have played the lottery that week too!"
This assumes that the sex of any one puppy is independent of all other puppies. Would any of the biologists on the forum care to comment on it?
I think breeders will cover their bitches on several days during the peak fertile time rather than it being a one-off. My understanding is that most puppies are born with their own placenta/sac so are fraternal, not sure how the repeat covering would influence this. No idea about the maths. No great shakes on the doggy biology
I'm not a biologist or anything close so would be interested to hear. I bet Rachael has some thoughts - @Oberon? I've heard that testosterone from male pups can influence character of nearby female pups; I wonder if there's any impact on determining the sex of other puppies in the same litter, even if they're fraternal. You would think if that were the case, there would be significantly more puppies of one sex than the other being born.
I am a Puppy Raiser for SA Guide Dogs in Joburg, and over the years they have had a few litters of all girls or all boys - although they are usually small litters or two to four pups. There was once a litter of 7 girls though!
Hmm, very interesting. My immediate thought was that the sex of one puppy would be independent of all others. Really interested to hear from someone 'in the know'. I might be an accountant but biology was the subject that always had my heart.
Thanks for all your very interesting input guys, I don’t have a dog at the moment, I’ve had spaniels in the past, but wanting a chocolate Labrador bitch, a local breeder i know has a chocolate bitch coming into season in the spring for her first litter, i know this dog, and yes, she does have a choc’s “character” lol, but one of her other black bitches had a litter of all boys a few years ago, so i was just wondering what the chances are, because I’d really like a bitch, impressed with the maths Joy !
Colour of course adds another variable to affect the odds! There’s a good article here explaining the genetics of colour in Labs. https://www.thelabradorsite.com/labrador-colour/ Good luck -fingers crossed for a chocolate bitch in the spring.
