I volunteer at the local shelter. I feel bad about not being able to take them home, but I walk out the door feeling good that I was able to walk/play/interact with them. It sucks they live in a small cage because their owners were assholes and didn't fulfill their obligations to their pet.
I get pissed when I see people drop off dogs they've had for years for bullshit reasons. Many of them are pits, and unfortunately, pits often will die in the shelters.
I'm with you mpress, I donate lots to animals...but not a penny to medical or human related charities.
If you care about animals, I highly suggest you visit the local shelter to drop off some food, newspaper, or to walk the dogs. The animals will appreciate it.