Hi all,

I know (or I think) a lot of you are experienced breeders so I thought someone might know the answer to this.

How common are multiple sired litters? Does it happen more often than people think or does it have to be planned (like with AI or two studs within a certain number of hours/days, for instance). Also are there usually a larger number of pups in a multiple sired litter?

The reason I ask is that I rescued a pregnant female. I didn't even know she was pregnant at the time so it goes without saying that I don't know who the dad is. She was dumped in a rural area so may have had access to multiple males, or may have been pregnant already when dumped.

She gave birth to four puppies. Since I know nothing about multiple sired litters (thinking only 4 puppies is unlikely to have more than one dad) and I *do* know something about colour genetics and inheritance, I assumed there was one father.

Now i'm beginning to wonder. All four puppies look very different from one another, and behave differently. I had one puppy genetically breed tested and it showed NO border collie, but a littermate looks like a border collie and even does that pose they do with the head lowered and staring. None of the other pups do that. One guy looks exactly like an English pointer. All of the pups have very short, single coats.

The mother is a Catahoula/Boxer/terrier mix.

The puppies have a classic Mendelian distribution of colour pattern inheritance. There is one pup who has full expression of the piebald gene, two that have partial expression (Irish spotting) and one that has no expression (minimal white). Which I thought meant that they were all full siblings. Or does it?

Okay, kinda off subject..but not..

Explain to me how the heck a bitch can be impregnated by more than one dog and come out with different pups from different fathers! I have heard this before and thought it fascinating but could never quite understand it from a biological standpoint.

Does the female always have eggs in store? Or when the female is in heat, just accept any and all sperm as long as it is within a certain time frame?

Sorry don't mean to hijack, just wildly curious about this.

I don't know how common it is. Most people obviously don't plan it that way.
The eggs can be released over a period of a few days. If male #1 mates first and fertilizes eggs that have been released, male #2 can still mate hours later, or the next day, to fertilize later released eggs. Low sperm count or motility in the first male could also leave released, unfertilized eggs for the next male that comes along.
I once read about a woman who had twins (in the same litter:laugh who had different fathers.

There are some people who purposely do this for various reasons in the AKC. AKC allows dual sired litters. I know of one breeder/judge who had a breeding with some frozen semen out of a long dead dog that "woke up" poorly (20%)and due to this, they choose to also use semen for another sire as well to hopefully ensure that they got *some* puppies. But what they did was during the surgical implants they split the semen between the two uterine horns -- one sire on one side and the other on the other side. That way (according to them) there wouldn't be any competition between the sperm.

Part of the reason for splitting up the semen between horns was because older/weaker semen would be no competition for more, shall we say, virile, semen ;-)

I have never done a breeding like this so I am only reporting what others have told me.

Wow! Absolutely fascinating stuff! This has been a good week for me! Learning so much! Thanks for those explanations, ladies

I'd be really curious to know if my litter all has the same dad. The only sure way to know would be to DNA test each pup in the litter, but at $80 bucks a pop, ain't gonna happen.

Robbin, multiple-sired litters is extremely common in cats. I read somewhere that most cat litters are multiply sired. I have personally witnessed some stray cats in my neighborhood mating - it was one female and three males. All three males mated with her. I just am not sure if it happens with dogs - as you don't often see dogs lining up to mate with a female. (One dog drives the others away, usually).

Multiple sired litters were always entertaining in the school yard when I was in grade school. Nuns flying around, screaching and slobbering, and swatting us in the head. Telling us we we're all gonna go to he(( if we kept watching that. LOL!

ROTFL Ok Bob. That is so the quote of the day.

Actually with dogs its fairly common outside of breeders if you look at the number of mixes in the shelters. I personally have seen two multiple sired litters (accidental). Where someone bred a lab to another lab and had the neighbors dobie hop the 6 foot fence in the middle of the night. The DNA services weren't available at the time so they sold the entire litter as mixes. They ended up with two dobie mix pups and the rest lab. The other was my neighbors loose dog when I was a kid who must have got knocked up by every breed known to man. Poor girl had 10 pups, they appeared GSD mix, husky mix, lab mix, pit mix, and something that appeared to be hound of some kind.

I know it's kind of nice to know what the dog is a mix of for value reasons but I just don't see the point. A mutt of that many mixes is a mutt is a mutt. Not that they can't be awesome pets but I wouldn't stress it because there is no way to be sure. The only thing you're kinda guarenteed of in that much unknown is that it belonged to the family Canis.

Strangely the dogs weird egg release is why it's so difficult to clone dogs compared to cats and other animals.

I’ll second Melissa’s experiences. Multiple sires are quite common when dealing with free-roaming dogs.

My family once “rescued” a pregnant black and tan shepherd/husky? mix from our neighbors who let her have free run of the neighborhood (and were starving her to boot). She had nine puppies: 2 black-masked agouti tans, 2 bicolors, 2 blacks (dominant, I assume), 1 recessive blue, 1 spotted tan, and 1 spotted bicolor. The 2 tans and the spotted bicolor puppy looked exactly like two males I recognized from the area.

I saw all three of the tan puppies grow up. The masked ones looked shepherdy and the spotted one looked houndy, so I doubt they were full siblings. I guess the three bicolors were probably all full siblings though. Assuming the blacks were dominant would mean that the litter had at least three fathers, probably four, and possibly as many as six.

I personally, though with limited experience, have never seen a male dog run off other males or guard a female he has mated with (other than guarding his territory). Though of course they will definitely fight for access to the female.