Washington Revised Code Title 11. Probate and Trust Law § 11.118.020. Validity of animal trust

A trust for the care of one or more animals is valid.  The animals that are to be benefited by the trust may be individually identified, or may be identified in such other manner that they can be readily identified.  Unless otherwise provided in the trust instrument or in this chapter, the trust will terminate when no animal that is designated as a beneficiary of the trust remains living.