To argue against animal abuse, you want your thesis to clearly state that you're against it and why. Your opinion should be a part of the thesis statement, but you want to be careful to actually present arguable, logical points, as well. You could say you're against animal abuse for a number of reasons. For example, some common ones are that animals feel both physical and emotional pain (abuse is cruel), that animals can't defend themselves and people should care for them because of their innocent nature, and that animal abuse can lead to further deviant and criminal behavior - including harming people. Don't forget that animals are also used for medical testing, and many people consider that abusive, too. You can pick only one main point when you argue against animal abuse, or you can pick several points to touch on. That decision should be based on how much evidence or information you have for each point, as well as how long your paper will be. A sample thesis statement could be something like: "Animal abuse is wrong and should be stopped, because many innocent animals suffer and die needlessly every year from medical testing and other forms of cruelty."
