[salana]

Spaying a pregnant animal is a harder surgery than spaying a non-pregnant animal. Spaying during heat is harder too, but probably not as hard as spaying during pregnancy.

A guinea pig's ovaries are very small. Basically the guinea pig uterus is shaped like a fleshy tuning fork, and the fallopian tubes and ovaries are just little strings at the prong of the fork. The two parts of the uterus are filled with little lines of babies when the animal is pregnant. (Humans have a round uterus because we typically only have one baby). It is much easier to see guinea pig ovaries when they have giant cysts (which may stick to the uterus and wrap it around themselves).

Why would you want to leave the uterus, anyway? Without the ovaries, it's just going to be at risk of infection or cancer. Suzi's uterine stump grew its own cyst after her first spay, so she had to have another. I'm not sure a uterus full of babies would be able to deliver them and recover without ovaries to make hormones.