without their deaths, I know that medical science wouldn't have advanced to the point where we can someday do without them
Right. That makes a lot of sense.

Well, it is indeed sad that these animals are sacrificed on the altar of science. However, I thank them, because without their deaths, I know that medical science wouldn't have advanced to the point where we can someday do without them. I don't however condone outright kidnapping of peoples pets to satisfy this need.
Thousands die every day for no reason at all, where's your bleeding heart for them?

You should check out the HBO documentary "Dealing Dogs". Dogs are sold from shelters or pets are stolen from neighborhoods to be sold to research labs. It happens all the time. Go to Peta's site if you're interested in doing something. www.peta.org

You only need to look as far as Senate Majority Leader Bill Frist to see animal experimentation. He worked on a mitral valve by using improperly obtained cats. (He lied to the shelter to get the animals.) To quote Senator Frist: "Desperate, obsessed with my work, I visited the various animal shelters in the Boston suburbs, collecting cats . . . it was a heinous and dishonest thing to do."
http://en.wikipedia.org/wiki/Bill_Frist_medical_school_experiments_controversy

I asked a nurse at a major cancer hospital why only one of the six elevators had a button for floor 13. she told me because thats where they kept the animals. she even told me that they bring the animals in at night to avoid protesters. so yes they did then and still have animals at certian hospitals.

COMA was written by Robin Cook.
It was adapted to film by Michael Crichton.

Different animals are sometimes chosen for their similarities to human systems. Eg. i think Rhesus chimps have similar cardiovascular systems, and rats, pigs (i think), and other random animals are chosen. Dogs prob too for the reason stated above.
Sounds cheesy, but I read it in a michael crichton book, but sounds like he knows his stuff.
http://kevan.org/brain.cgi?Shuffle

Unfortunately, it's true. I do know that teaching hospitals, such as this one, have doctors practice surgery on stray dogs that would normally be euthanized at shelters. It's sad but true. When I saw that my heart sank. Personally, I could never do that. I guess that's why I'm not a doctor. And the fact that I barely passed science in high school and college.