Rather strange question to be honest and it's out of interest more than anything else...not being familiar with animal sexual organs.

When a male human has an orgasm the penis tenses and pumps the sperm out however on any video you see the penis of an animal doesn't seem to do this - especially horses. They can seem to almost be flaccid, do their penises not throb...I suppose when ejaculation occurs?

Most of the cumshot videos are faked. A horses penis flares when he cums, and it's quite a visual experience. If you browse around this site you'll find plenty of real cumshots that put the fake ones to shame.

You are so correct, Magelus, I have seen how much a horses penis can flare. Also, I have noticed that when a horse is rock hard when he cums, there isn't such a pronounced exansion, but it is still quite visible and pronounced - especially at the end of the shaft where it mushrooms out quite a bit. I get so turned on watching the reaction from a woman when this happens inside of her.
I can tell you that without a doubt, a dogs penis does throb - and trob and trob throb throb ... :lol: :)

Each species's penis is different. Equines, canines, and humans share a common trend of being blood-filled. Other species, such as cervine, bovine, ursine, etc, are fibrous, and do not fill with blood. Some such as dolphins and elephants are prehensile.

As far as pulsing, the pretty much all do :) That's caused by the pressure of the semen as it moves through the organ. You may not be able to notice such pulses in some though. Others, such as humans, dogs, and horses, the pulse is caused by a contraction of a muscle (one not even in the penis, actually... its around the base of the penis up inside the body) rather than semen. Horse's penises do expand and pulse, and that's due to how the blood moves in the organ as the ejaculation takes place. Blood and muscles control all equine penile actions, not the semen. :) Its really kinda cool.

If any animal would be to cum when not erect/tied/arroused, there is no guarantee that his sperm would drip out of the female (or rather the recieving end :lol: ), which would mean that there were less chances of impregnation which is what sex was made for... that we animals have found so many other uses for it is entirely up to us!

In porn industry there are things you MUST do, like all the mainstream movies that have a lesbian sex scene, a cumshot belongs to those MUSTs, but having a 1000 lb horse cumming on a 100 lb model is... shall we say dangerous?, a simple thrust from the stallion might kill the lady (as a matter of fact, this was a way to execute persons in old Rome, and has caused fatalities among the zoo community), so what they do is to fake the shot. Anyway, most of the human actors are not zoos nor beasties, and you can see that in the way they react to animals, as a girl using a condom to blow a dog, or the girls that seem to be robots while handling horses.

Amateur porn is quite another animal, in some scenes you don't get much of a camera view, a script or angle, but you see people and animals giving pleasure to themselves, really enjoying it and looking to please their animals... and even in some cases even real cumshots :lol:

I'll have to wait until I can afford to watch the real movies here again. :(.

you can always check out the free daily downloads. ;)