If people want to give to an animal charity rather than "human" ones, then they should be supported whole heartedly. There is no reason why people should feel pressured to give to charity at all, so if they decide to give a generous gift to ANY charity that is a good thing. Pressuring people into giving money to specific causes by trying to make them feel guilty is simply wrong. It's the kind of tactics used by "chuggers" who I absolutly despise.
Personally, I prefer to give to charities that are likely to affect me and my family. Does that make me selfish? Probably. Do I care what other people think? NO.