Yes, you can sue. I would do more than going to small claims court. I would consult a personal injury attorney in your area. I would also report the people to animal control. If you don't someone is going to get seriously hurt.
Contact Pierce County Animal Control. This behavior satisfies the definition of a "dangerous dog" in Washington. Keep reporting the incidents until animal control does something about it. You could also put up a fence. I'd be careful about shooting it with a pellet gun. You could end up with an animal cruelty complaint.
You should have a business license, insurance, and possibly create a business entity. The Washington State Bar Association Animal Law Section is having an all day seminar on equine law on January 29, 2013. It will cover topics of interest to you including insurance issues relevant to stable owners and trainers. We have a special rate for nonattorneys. For more information go the the Washington State Bar website and click on January 29, 2013 or give the bar a call.
If you hardly have the funds for a legal battle, then at least have a lawyer review any agreement that he wants you to sign. You don't say whether your ex is an ex boyfriend or ex-husband which definitely makes a difference. Don't go to small claims! They can only award monetary damages.
If the minor's doctor agrees that the child requires a support animal, then the Fair Housing Act applies. She needs a letter from her doctor stating that she is disabled and requires a support animal to allow her to enjoy her dwelling. The landlord is entitled to some evidence of a disability and to some evidence that a support animal is necessary. Her mother should be careful not to take advantage of this exception under the FHA. It is provided for individuals who truly need the assistance of...
I agree with both of the answers that you have received so far. One must consider the length of time that you left your cat in the crate and the size of the crate. If the crate was too small, it could be considered animal cruelty. If you left her in it for a long period of time, this too could be considered animal cruelty.
Under the FHA, you are entitled to a reasonable accommodation. It doesn't matter what breed your dog is. Even if the ADA or Washington Law Against Discrimination were applicable in the context of housing, the regulations are clear that the breed should not be determinative. Your dog does not need to be registered as a service dog. Your landlord is entitled to a letter from your health care provider stating that:
You are disabled
Your support dog ameliorates your disability
You require your...