I donate to my local animal shelter, in the form of dog food, bedding, toys, etc...
That way I can control what my money is spent on.
If you give at the source...it is wisely spent. That cannot be said for about fifty percent of all charity operations.
I donate to an organization that works to establish trap/spay/neuter/release programs across the country. The innocent little animals deserve our compassion. Plus, feral cats help control vermin.