Over half of the litter dead.

[Christopherreptile]

Hello,

My first posy here and unfortunately it's a sad one. This mother most likely isn't a first time mom. She had 5 babies alive and 7 dead by the time I found the litter. Can anyone think of a reason why?

[Bogertophis]

Since you don't know the history, I'm assuming this might be the reason her previous owner didn't keep her- age or other factors that negatively affected her reproduction. Not every animal (or human, for that matter) reproduce successfully- sorry this didn't work out better. Were the babies undersized? Any visible defects? (I'm assuming they had no injuries from the mom?) Was the rat fed well? What about handling &/or stress? Fighting with other rats? (kept alone? or with others?)

[Lord Sorril]

This mother most likely isn't a first time mom. She had 5 babies alive and 7 dead by the time I found the litter. Can anyone think of a reason why?

First 5 came out fine, #6 got stuck in the birthing canal and resulted in the remainder being born deceased.

Sometimes this is bad luck, sometimes this is due to the female being overweight and/or old.

[Armiyana]

Rats and mice are actually highly prone to dystocia/difficult labors. So as mentioned by Sorril, one getting stuck in the canal could have caused this for sure.

I actually just had to separate a first time breeder female out for what I thought was just a low birth rate at first, but when I checked back in with her the next day, she had eaten all her babies. The female that had been housed with her dropped 16 healthy babies, so *shrug*. She'll be culled from the breeding group because I don't want the possibility of that trait continuing.
Sometimes we really don't have a reason why they end up as they do.

For the best production for breeding, you ideally want to shuffle the male between groups of females. For the moms, give them a week or two to recover after taking away the weaned litter. The faster she gets back into breeding, the more likely she'll be to have a lower production or issues with the pregnancy.
I cycle one male in a 5 tier rack. Every two weeks he gets shuffled to a new row. That gives my girls a little time to fatten back up a bit before they get bred again.

[Christopherreptile]

Interesting, thanks for the help, I'm trying to figure out how to insert an image, one of the babies does look sort of deformed. I feed rodent block with "rat mix" (sunflower seeds, corn, etc) mixed in the bedding every change. I've had aprx 8 other females give healthy litters ~8 pups several times. The blocked canal makes sense. An interesting behavior I noticed was that she was "stealing" almost fully weaned pups from her roommates litter she had been living with for weeks before the birth. I keep no more than 3 females per cement tub and 1 male to cycle through them

[Bogertophis]

Interesting, thanks for the help, I'm trying to figure out how to insert an image, one of the babies does look sort of deformed. I feed rodent block with "rat mix" (sunflower seeds, corn, etc) mixed in the bedding every change. I've had aprx 8 other females give healthy litters ~8 pups several times. The blocked canal makes sense. An interesting behavior I noticed was that she was "stealing" almost fully weaned pups from her roommates litter she had been living with for weeks before the birth. I keep no more than 3 females per cement tub and 1 male to cycle through them

Babies get injured, even killed, when moms fight over them- their fragile bodies aren't designed for "tug-o-war". I'd recommend no more than 2 females kept together to minimize that, & be ready to separate them if they don't work out- some are great together, but not all. Baby-stealing is common.