RCW 16.54.010: When deemed abandoned.

An animal is deemed to be abandoned under the provisions of this chapter when it is placed in the custody of a veterinarian, boarding kennel owner, or any person for treatment, board, or care and:

(1) Having been placed in such custody for an unspecified period of time the animal is not removed within fifteen days after notice to remove the animal has been given to the person who placed the animal in such custody or having been so notified the person depositing the animal refuses or fails to pay agreed upon or reasonable charges for the treatment, board, or care of such animal, or;

(2) Having been placed in such custody for a specified period of time the animal is not removed at the end of such specified period or the person depositing the animal refuses to pay agreed upon or reasonable charges for the treatment, board, or care of such animal.