Everyone who considers themselves an activist or advocate knows what it's like to have a "pet cause"--either because they have one themselves, or because they know someone else who does. For me, rather obviously, it's animal welfare. I care deeply about the welfare and ethical treatment of all living beings, but animal welfare has taken top priority in my activism because of the billions (literally) of individuals that humans purposefully, systematically, and unnecessarily brutalized every year.
However, one thing I've come to realize in my search for compassion, is that we (the activists of the world) need to embrace the idea that we are capable of supporting more than one cause, and before we go proselytize a particular cause of choice, it is important to make sure we are doing everything in our power to live in accordance with all of our own values. Causes, especially social justice causes, are all interconnected, and all are essentially fighting the same battle--the battle against the perpetration of hate, the battle against the -isms (be it racism, sexism, speciesism, etc.), and the struggle for equality and freedom.
I've known many activists (myself included) who have at times become so engrossed in their own pet cause that they neglect other important issues. Dedication to a cause does not excuse people from educating themselves about issues that lie outside the realm of their immediate interests. Before we can ask others to change their lives for our cause, we must make sure we are not contributing to other injustices in the world, so that our own lives set an example of balanced morality, not hypocrisy.