Here is some more information on how to report Animal Cruelty in WA state:
https://www.paws.org/get-involved/animal-cruelty/ Reporting cruelty
Even if you are not sure that you are observing animal cruelty or neglect,
please report it anyway. An animal control officer will make that determination. If no prosecution occurs, at least the officer can educate the person who is caring for the animal in humane treatment.
When making your report, ask for the name of the animal control officer and what action is planned. Follow up, and report any change observed in the animal's treatment.
Be aware that an investigating officer is not likely to identify the source of the complaint; however should the cruelty suspect be prosecuted, you may be called as a witness. Your concern for the animal should outweigh your concern about having to testify.