If they did it before they will likely do it again. Animals feel pain and have emotions and it is wrong to harm them. So if you are convicted of abusing them you should be banned from having pets. You do not deserve the joy of having a pet if you enjoy harming animals.
It's the same principle of having a kid, it's a an enormous responsibility and if your child dies or is injured because you were careless (left in a car on a hot day or died because their parents favored prayer over medical treatment), that proves you're not responsible enough. A few people have gotten into trouble with the law for neglecting their pets (left their dog outside in subzero temperatures). Well, that's their own fault.
Animals that are ours are ours to do with as we see fit. If that extends to neglect/abuse, so be it.
Give an argument based entirely on pragmatism (so a logos-only argument) exactly WHY the above is false, and I'll listen to you. Otherwise, take your bleeding heart and bleed to death already.