Whenever there is a major disaster like the earthquake in Haiti, animals suffer as well as people. Both the people and the animals of Haiti had it rough before, so certainly it is a terrible time for them now.
If you want to help the animals of Haiti, I suggest donating to Best Friends, which will work on both short term and long term animals in Haiti and has a team of trained personnel. Here is a specific link to donate to assist with animal issues in Haiti.
While they are also looking for volunteers who meet certain criteria (including being able to be completely self sustained and responsible for your own personal security), volunteering may not be the best option. Here is an interesting piece on the problems that can come about when inexperienced people with good intentions volunteer on the ground.
I certainly feel for the very poor people in Haiti who have had to endure this disaster again, so I donated an equal amount to Doctors Without Borders, which I felt was in the best position to assist in ways I think appropriate in this particular circumstance.
If you choose to give to some relief efforts, I would recommend checking out the charities of your choice on Charity Navigator. There you can obtain information about how your money is likely to be used - what percentage on relief vs. fundraising or salaries or administration, etc. If you can't obtain this information, you can't guarantee the money will be used in the way you intend. Make sure the charity is legitimate and will make the most of your money BEFORE you give.