I just read the article on chupacabras. I had only recently heard of them when someone I know mentioned the phenomena. I have never studied cattle mutilations or big foot or anything like that. I just looked up chupacabras on the Internet to see what it was. I read the article here suggesting that there is no blood around the scene of the carcass due to the settling of blood from the heart stopping after death. However, when I think of the phrase “drained of blood” I think they mean that when they opened it for inspection, they found no blood inside of the animal. Is this article suggesting that they never bothered to open the animal and they’re just assuming there is no blood inside of the animal because there is no blood around the animal? I didn’t take it that way because the description includes nothing but two small wounds (like a bite), so why would they think there would be blood around the carcass in the first place? Does anyone know if the Nicaraguan people or the Puerto Rican people actually opened the animals? And if they did, is it normal for there to be little blood when opening a killed animal, or is that an unusual thing? I’m totally confused by the blood-settling argument, but I’d like to see SOME kind of argument to put this stupid chupacabra theory to a rest. Can someone who knows more about it please help explain?
Also, I’m pretty much a city person, obviously. I’ve never hunted before or anything. Is it a common occurance for there to be no blood around a killed animal? I wouldn’t think so, but the blood-settling theory suggests that it would be the norm rather than the exception for there to be a lack of blood. 
Welcome to the Straight Dope Message Board, Always glad to have you with us.
When you start a new thread, it’s helpful to others if you provide a link to the Staff Report that you’re commenting on. Helps keep us all on the same page. In this case, it’s Can the mysterious chupacabra of Puerto Rico suck the blood of farm animals?
I’ll let someone who knows something about it try to answer your questions.
It’s been a while since I researched and wrote that (three years!) so I must admit that I don’t recall all the details. However, indications are that no, nobody has actually opened it up and looked for the blood. But even if they had, unless they had somebody trained to do autopsies (or necropsies or whatever they’re called when you do it to animals), it might have the same result. The blood of a dead animal pools through gravity. So if you cut it open, it would indeed look like the blood was gone. Where did it go? Down. So if it was found lying on its left side and you cut open its right side, you’d find little blood. You’d have to turn the animal over and find it all pooled on the left.
If you’ve ever watched CSI or the like, you’ve probably heard them talk about how they know when a body has been moved because the blood pooled in a place that it wouldn’t have under natural circumstances. Same concept.
All in all, the folks who have spread the Chupacabra story are not exactly at the CSI caliber. If we had a Gil Grissom to take a look at the animals, I’m sure he would find the blood and be able to explain it. But when you have people who think alien monsters are sucking their farm animals’ blood, scientific processes are probably not super-high on their list.
And CSI is not exactly at the real-life forensic scientist level 
Good explanation tho…
It can also depend on how long after death the necropsy is performed. Blood is almost entirely water, and it’s actually designed to clot up and dry out. So if a carcass is lying out for a few days, you may not find any blood anywhere. You may find a lot of clots on the part that was facing downwards – and in fact during autopsies the location of clots becomes very significant because it can indicate the position a body was in, although it really only works if the body was allowed to stay in that position for a few hours. Basically, it can reveal whether a person actually died in the position in which they were found. These clots can be mistaken for bruising, so if a dead animal seems to have been badly beaten on the side that was lying down, that just might be where the animal’s blood ended up.
A grim side-note: my father is a doctor who sometimes works weekends at a small-town emergency room. It’s usually pretty quiet, but one weekend he had the misfortune of needing to sign the death certificate for a teenaged boy. He said he didn’t even bother checking for vital signs; when he arrived on the scene, the boy had a huge gash that wasn’t bleeding at all. If a person has a deep, bloodless cut, it means they’re dead (or otherwise have no blood supply to the cut); all the blood can only sink to the lowest part of the body, actually siphoning out of tissues in the process as the pressure drops off to nothing with the stopped heart.
Another side-note: when animals are slaughtered according to Jewish custom, all of the blood has to be drained out of the carcass. The only way to assure this is to drain it as fast as humanly possible after death. Blood congeals fast in a dead body.