Do animals menstruate?

July 1, 2008 6:22 PM

Do animals menstruate?

More specifically, are there non-primate mammals that shed their uterine lining in a manner analogous to menstruation, either seasonally (if they have a seasonal cycle), or year-round? Also, are there non-primate mammals that bleed in a manner similar to menstruation, but stemming from another biological cause (i.e., not a shedding of the uterine lining)?

posted by kyrademon to pets & animals (17 comments total)

Yes.
posted by meta_eli at 6:27 PM on July 1

Yes, but not like humans. Most animals' linings get absorbed and there's no period/bleeding.
posted by phunniemee at 6:30 PM on July 1

Dogs do. They even have special pads in pet stores for the bitches when 'Aunt Flo' comes to visit.
posted by spinifex23 at 6:32 PM on July 1

Sort of. The term you're looking for is 'estrous cycle.' The cultural implications of human women not being blatantly 'in heat' are, according to some anthropologists, really significant.
posted by cobaltnine at 6:46 PM on July 1

Estrous
posted by Science! at 6:46 PM on July 1

I read that wild dogs and wolves don't menstruate very much blood, if any... that in domestic dogs it is caused by an unnatural diet. Same with primates, who do menstruate, but lose very little blood. Raw foodists and paleo dieters often cease or have less bleeding.
posted by melissam at 6:47 PM on July 1

No. Only (some) primates menstruate. All other placental mammals have an estrous cycle. Aside from slight bleeding in some species--particularly domesticated ones such as cats, dogs, and cows--mammals with estrous cycles do not bleed. Instead, the lining is reabsorbed if fertilization does not occur.

Check out the Encyclopedia Britannica entry on the subject. (Note: annoying pop up every several seconds unless you are a subscriber).
posted by jedicus at 6:49 PM on July 1 [2 favorites]

Most mammals undergo an estrous cycle instead of a menstrual cycle.
posted by cinemafiend at 7:03 PM on July 1

Should have previewed.
posted by cinemafiend at 7:04 PM on July 1

...and of course, just so we don't confuse being "in heat" with menstruation, estrous manifests at the midpoint of the cycle, when ovulation occurs.
posted by gaspode at 7:27 PM on July 1

My dog experienced estrous about four to six times a year before we finally got her fixed. It was h-o-r-r-i-b-l-e. She bled everywhere. The final straw was when she experienced a false pregnancy. We were trying to save money at the time for our big move back to Canada, and also thought it might be cheaper to fix our dog in Canada rather than in Japan. Were we ever wrong. Although I suppose we made a mistake by taking our dog to a "holistic veterinarian" in Canada. Are all vets such money-grubbing scum?
posted by KokuRyu at 7:42 PM on July 1

This is a slight derail, but the relationship between menstruation and raw food in humans is almost certainly a reflection of a reduced caloric and fat intake [pdf], and nothing mystical about the "naturalness" of cooking food. It's likely that the same principle holds in domestic cats and dogs, who eat an abundance of food relative to feral or wild relatives.
posted by nev at 8:03 PM on July 1

Wow, KokuRyu, my dog also used to bleed everywhere, and also had a hysterical pregnancy. Yes, domesticated dogs definitely menstruate.
posted by crinklebat at 9:04 PM on July 1

Yeah they do. When I was working as a slave-labor clothing salesperson on Melrose in L.A.I was regularly asked (via phone) by my boss to wipe her effing poodle's menstrual blood off her ass.

I got fired. the carpet suffered.

Hopefully she's (not the dog) is suffering somewhere as well.
posted by Kloryne at 9:17 PM on July 1

Aren't eggs chicken menstrua or is that apocryphal?
posted by turgid dahlia at 10:15 PM on July 1

No, they are eggs.
posted by fshgrl at 12:29 AM on July 2 [2 favorites]

It depends how you define "menstruation", but dogs do NOT technically menstruate, the blood seen during the proestrus phase of the dog heat cycle comes from the vaginal walls, not the uterus. Menstruation is the shedding of the endometrial lining through the vagina, dogs reabsorb the endometrium, they do not shed it through the vagina. Animals with an estrous cycle do not menstruate, only animals with a menstrual cycle menstruate (humans and some primates, plus some others).
posted by biscotti at 5:09 AM on July 2