Do people test drugs on animals?

All of them, it is a requirement to test on animals before testing on humans. This prevents human deaths, since it's impossible to know the effect of a chemical on a living body without testing it. Some of the animals used for testing are: rats, mice, cats, dogs, rabbits, monkeys, apes, pigs and bears. There is a growing trend among some scientists to advocate for limiting the use of animal testing to only research that cannot be done with virtual simulation or in vitro testing on cultured cells(test tubes with blood in em, to see how cells react).

A first stage test is now rarely done on lab animals, virtual systems and in vitro tests can substitute for testing on animals when testing to see if a substance is broadly toxic. However, virtual and in vitro testing cannot give much more information than toxicity as virtual models are still limited, and many effects cannot be guessed simply by observing blood chemistry changes. Animal testing still needs to be done to test for things such as the LD50 (dose at which 50% of test subjects die) or more subtle/rare effects, such as 30% of test subjects experiencing heart palpitations, something that you can't find out with blood chemistry or computer models, but that would cause a big problem if it where marketed.

Animal tests can only tell us so much, as their physiology is different from ours, so human testing still needs to be done before something hits the market, and many things that used to be tested for on animals are no longer tested for, and many effects on animals are even ignored because of this, since animal testing in those circumstances realy does not teach us anything useful. Something may cause no effects, or severe effects in rats, but may act completely differently on humans.

As a whole, animal testing has been greatly reduced in recent years, but will probably never be wholy elliminated from the process of testing new drugs, as it is still preferable for most people, to kill a rat, than to kill a human. As our knowlege grows, we will surely reduce it even further.