Rather than donate to a large bureaucratic organization, you might consider researching your local animal rescue groups. Just about every breed of dog has a rescue group in just about every major city, and your $ will go a long way to help a locally-run rescue group or no-kill shelter. If you wish to help animals in the wild, again, I prefer to give "locally" because the $ is going to underfunded projects with dire need. I prefer to fund groups run by volunteers that I can trust not to have large administrative overhead. One example is Conrehabit in Mazatlan; I like them because they rescue animals threatened by vacation resort development resulting in destruction of habitat. They also rescue wild animals and birds stolen by poachers for sale in the pet trade.
I want to applaud you for continuing your annual giving, when the need is especially great this year and giving is generally down. Happy holidays to you!