How to become a Saint

In a previous post I was ruminating on the imminent sainthood of the deceased Pope John Paul II.

Further research has revealed that the Catholic Church has over 3000 saints.

There is an alphabetical listing here.

My interest has been sparked as to how one becomes a saint?

Looking at this issue from a uniquely Australian point of view, the question arises of can an animal become a saint?
Specifically I am thinking of the legendary donkey who accompanied Simpson during WWI and carried many wounded soldiers in the trenches. It is a familiar story to all Australian children and there is an indelible image of Simpson and his donkey carrying wounded, that is still in my mind.

Another example would be Phar Lap. This was a racehorse of mythic proportions who was seemingly invincible until some dastardly Americans decided to poison this racehorse.
Phar Lap has been lovingly stuffed by a taxidermist and his skin graces the glass cubicle in a Museum here in Australia. This would surely be a candidate for canonization.

Then of course there is Australia's most famous cricketer, Sir Don Bradman. A saint amongst Australia's sporting cognoscenti. Any item of his clothing can fetch a small fortune on ebay.