I'll vent a little:
I think that by engaging in animal testing we are like persons who, when being threatened with a gun, violently grab innocent bystanders (e.g. children) to use as a cover. Us suffering and dying from diseases (despite being tragic and something that hopefully will be helped in an ethical manner) gives us no right whatsoever to cause suffering and death to other sentient beings.
To paraphrase and possibly expand Isaac Bashevis Singer's views:
What is our real "justification" to animal testing? It's that
1) non-human animals don't belong to the same group as us. They are different, and we have compassion only for our "own kind", never mind any ethical similarities.
2) we have the power to kill and torture.
This is also the basic structure of the "reasoning" racists have.
--
One of the strongest quotes I know against vivisection is this:
"I am of the opinion that not one of those experiments on animals was justified or necessary...I witnessed many harsh sights, but I think the saddest was when the dogs were brought up from the cellar to the laboratory. Instead of appearing pleased with the change from darkness to light, they seemed seized with horror as soon as they smelt the air of the place, apparently divining their approaching fate...
Hundreds of times I have seen when an animal writhed in pain, it would receive a slap, and an angry order to be quiet and behave itself...To this recital I need hardly add that, having drunk the cup to the dregs, I cry off, and am prepared to see not only science, but even mankind, perish rather than have recourse to such means of saving it."
-Dr. George Hoggan (assistant to vivisector Claude Bernard).
"and I stand
upon a mountain
made of weak and useless men"