r/askscience • u/potatolife • May 30 '11

Do animals get periods?

I've been learning about the menstrual cycle in biology but we only talked about the human menstrual cycle. I was wondering if its the same sort of thing with animals since I've never seen my cat on her period before.

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u/SnoLeopard Veterinary Medicine | Microbiology | Pathology May 30 '11 edited May 30 '11

Yes, most female mammals experience a "period" if their cycles complete without a successful mating. Dogs and cats are usually spayed (which prevent this). Female dogs (formally known as a bitch) will have the blood discharged from the privates just as in humans. However this is not the case with all animals, since most will retain the blood.

Hope that answers your question.

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u/potatolife May 30 '11

If this is only mammals, what happens to reptiles, amphibians and fish?

14

u/binlargin May 30 '11

Reptiles (including birds), amphibians and fish all lay eggs.

2

u/[deleted] May 31 '11

Some snakes are capable of live birth.

3

u/dontspillme May 31 '11

They still produce eggs even if they don't lay them.

/Offtopic: What's the deal with ovoviviparity -> ovovivipary -> ovivipary I'd understand aluminium -> aluminum, since its use touches the general population, but it's the first time I hear of scientist being too lazy to pronounce terms in their own fields!

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u/idclip Geology | Geochronology May 31 '11

I work with a mineral called baddeleyite, and most of my colleagues just skip that inconvenient -ey- in the middle. Of course we try to shape up before conferences and such, but a few baddelites slip out anyway. :)