As we all know, girls do not poop; only icky smelly cooty infested boys poop. Other female animals do poop. Ponies are intermediate between equines and apes.

Women menstruate, but equines evolved the ability to recycle their endometrium. Again, ponies are intermediate between equines and apes.

For an explanation about how ponies evolved, yet have chimeric features, not just intermediate between equines and apes, but in the case of pegasi, having archosaurian features, and in the case of hippogriffs, having archosaurian and feline characterists too, please read Going Aquatic by Pineta:

Going Aquatic
——
Pineta

It is 1 chapter of a multipart story. I recommend reading the whole story, as well as all other works by Pineta.

I contend that Doctrix Whooves, like a girl, does not poop, and, like a mare, does not menstruate.

Since it is the 1st, I wish you all an happy April.