Animals' rights & animal protection

Let's start with a distinction: what is the difference between animal welfare (or animal protection) and animal rights (or animal liberation)?
The traditional societies for the prevention of cruelty to animals of the past accepted that the welfare of nonhuman animals deserves protection only when human interests are not at stake. Human beings were seen as belonging to a separate moral domain, with a gulf between them and all other animal species, and infinitely superior to them.
If our interests conflict with theirs, it is always their interests which have to give way.
The new position puts human and nonhuman animals on the same moral footing.
This is what we mean when we say, as Peter Singer does in his book Animal Liberation, that "all animals are equal."

We come to the crucial point of a demarcation line in ethics.
What defines and bounds the beings to which we apply moral judgements, in contrast to the ones outside the scope of moral considerations?

This ethical demarcation line cannot reside in a biological factor per se. Membership of a species is one such biological factor; others are membership of a race or sex.
One of the reasons why biological factors are a dangerous demarcation line is that they annull individual differences: the actual characteristics possessed by the particular individual we are dealing with become irrelevant, and the individual is assimilated into the group to which it belongs.

About vivisection, we want to establish an opposition on ethical grounds.
To affirm only that animal experimentation is to be banned because it's damaging to human health (due to the risks involved in extrapolating experimental results from one animal species to another - the human animal) is to reaffirm non-human animals status as means to an end: human beings.
If we should abolish vivisection on those grounds only, what could be said and done about all other forms of animal abuse?
We wouldn't have a basis to combat those.

Besides, how can we be sure that no benefit has ever stemmed from animal experimentation?
It's an absolutistic position, very much like the position in defence of animal research is.

Neverheless, it's useful to point out the many cases in which it's wrong, misleading and, above all, it relates to the attitude of trying to avoid all risks.

Claims of usefulness of animal experimentation are often exaggerated. The higher the number of cases when we can dismantle the arguments of defenders of vivisection, the speedier the process of limiting and eventually banning this practice will be.

Why are animals important?

The question of animal treatment is an ethical question.