Why don't female animals have a menstrual cycle?

Question

What is it about humans that makes them different?

By mentrual cycle, I mean spewing blood out of it's bum. I've honestly never seen my [female] dog do that.

Answer 1

Human beings and Great apes have menstruation cycle. Other mammals have an estrus cycle. For dogs and cats and such, we call it "heat." But the heats stop when animals are spayed, and this usually happens when the animal is about 6 months old or so.
You see, all of the physical activity in our bodies is engineered to support the proliferation of our species... so we are given "cues" about what to do, and when. Humans are sexual creatures at any time, not just during particular phases of the menstrual cycle. However, it is easier to get pregnant at some times vs. others - so we have bodily cues and urges in order to increase our chances of getting pregnant. Primitively and instinctively, we are trying to prolong the cycle of life, so getting pregnant and having offspring is an innate human quality and ability. (This can be debated in a variety of contexts for a variety of social reasons... however, we are, first and foremost, humans - so the argument stands).
Animals that experience estrus are only sexually active during this period. Sexual activity is for proliferation of the species and is greatly enhanced when it occurs at the time that fertilization will most likely occur.

Answer 2

A regular menstrual cycle as described here only occurs in the great apes. Menstrual cycles vary in length from an average of 29 days in orangutans to an average of 37 days in chimpanzees.

Females of other mammalian species go through certain episodes called "estrus" or "heat" in each breeding season. During these times, ovulation occurs and females become receptive to mating, a fact advertised to males principally in some way presumably mediated by pheromones. If no fertilisation takes place, the uterus reabsorbs the endometrium: no menstrual bleeding occurs. Significant differences exist between the estrus and the menstrual cycle. Some animals, such as domestic cats and dogs do produce a very short and mild menstrual flow. However, due to its small amount (and personal cleanliness in cats) it passes pet owners largely unnoticed.

Answer 3

They have cycles called "estrus cycles".

However, other primates, like apes (orangutans, bonobos, chimpanzees, and gorillas) have menstrual cycles.

Here is some info about it from this site: http://experts.about.com/e/m/me/menstrual_cycle.htm

"Menstruation in other mammals
A regular menstrual cycle as described here only occurs in the great apes. Menstrual cycles vary in length from an average of 29 days in orangutans to an average of 37 days in chimpanzees.

Females of other mammalian species go through certain episodes called "estrus" or "heat" in each breeding season. During these times, ovulation occurs and females become receptive to mating, a fact advertised to males principally in some way presumably mediated by pheromones. If no fertilisation takes place, the uterus reabsorbs the endometrium: no menstrual bleeding occurs. Significant differences exist between the estrus and the menstrual cycle. Some animals, such as domestic cats and dogs do produce a very short and mild menstrual flow. However, due to its small amount (and personal cleanliness in cats) it passes pet owners largely unnoticed."

Answer 4

Simple; other animals do. I want to say all mammals do. You haven't heard of a breeding dog being on her cycle? Primates also have menstrual cycles; gorillas I think will eat a certain plant to ease menstrual cramps.

Answer 5

because no females menstrual cycle ever has a part in it where blood comes out of their bums?

Answer 6

you a ding bat or somethin?

Why to you suppose the female dogs and other species, has those longated periods, (no pun intended), curled in half, of licking themselves right below the ole bunger, at the same time every month.

Answer 7

All female MAMMALS have menstral cycles. Pick up any pet magazine, and you will find "piddle" pants and pads for dogs and cats. If it doesn't lay an egg, it has a cycle.

Answer 8

I presume that Your dog is desexed or has never been on heat?
Did You know that MALES also have a cycle too?

Answer 9

Where have you been ? Ever heard the saying "In heat ?"
What would you call that ?

Answer 10

haha, female dog do have their menses..but not as frequent as human being...haha, they even have their sanitary pads..