Superfetation?

morganafay

Does anyone here know anything about animals and superfetation?
I think it is pretty much, an animal getting pregnant when they're already pregnant.

This is really weird, but there's a girl one a guinea pig forum, who says her guinea pig had babies 10 weeks ago, she had removed the male from the cage a week before she gave birth. All the babies are female. The male hasn't been anywhere near her, the male is outdoors and females are indoors. But then this morning the guinea pig had more babies!

Guinea pig pregnancy is about 10 weeks long. So she was thinking superfetation but the guinea pig hasn't even been with a male for over 11 weeks, so unless this was a very very long pregnancy and the guinea pig got pregnant again a week before giving birth . . . that isn't really heard of in guinea pigs apparently though I know rabbits can get pregnant when already pregnant.

Does anyone know about this? I just find it so strange and interesting.

lrushe

Never heard of it in mammals only marsupials so I did a quick Google search and apparently it is possible in mammals so who knows???

morganafay

I know it is for rabbits, or an animal with two uteri, so that's kinda cool and interesting. There's the added mystery in this case of the extra long pregnancy, but I guess that's possible too! The girl is going to the vet tomorrow so it'll be interesting to hear what he says.

The Sweeper

Cats can do something similar; a female in heat can be mated by a number of different toms. When the tom withdraws, he has rows of tiny spines on his penis that rake the vaginal canal and the spasm that causes triggers ovulation. That means that a female cat can ovulate a number of times in one heat, because she'll be mated a number of times. That then means she can have kittens in a single litter that have different fathers. In a way, this could mean by definition that she's already pregnant and gets pregnant again, but it's probably stretching the definition...

The physiology of marsupials and reproduction is mind-boggling, especially kangaroos. They can put their pregnancies on 'hold' in times of scarcity, for months or even I think years, before resuming them when things get better and food and water are in abundant supply!

morganafay

Oh yeah I knew about cats.

That's really interesting about marsupials. Rabbits can do something similar, well not really as cool. If they mate but conditions are unfavourable or they have too few embryos, then they can reabsorb some because it would be a waste for them to get pregnant and only have a few babies. But the embryos are just reabsorbed, not put on hold for later.

lrushe

morganafay wrote: »

Oh yeah I knew about cats.

That's really interesting about marsupials. Rabbits can do something similar, well not really as cool. If they mate but conditions are unfavourable or they have too few embryos, then they can reabsorb some because it would be a waste for them to get pregnant and only have a few babies. But the embryos are just reabsorbed, not put on hold for later.

Dogs will also reabsorb a pregnancy. I've know breeders to have confirmed pregnancies only to have an ultrasounds done to count the number of pups and find out the pregnancy was reabsorbed, highly disappointing considering some breeders wait years to find and achieve a particular mating, I know one who imported semen from Spain only for the mating to be reabsorbed.