(1)    Except as provided in sub. (1m), a political subdivision or person contracting under s. 173.15 (1) may treat any animal taken into custody under s. 173.13 (1) (a) 1. as an unclaimed animal subject to s. 173.23 (1m) if, within 4 days after custody is taken of the animal, it is not claimed by and returned to its owner under s. 173.23 (1).

   (1m)   Notwithstanding sub. (1), a political subdivision or person contracting under s. 173.15 (1) may not euthanize the animal taken into custody under s. 173.13 (1) (a) 1. before 7 days have elapsed after custody is taken, except to alleviate physical suffering or to protect the safety of shelter staff, volunteers, or the public.

   (2)   Except as provided in sub. (3), a political subdivision or person contracting under s. 173.15 (1) may treat any animal taken into custody under s. 173.13 (1) (a) 3., 4., or 9. as an unclaimed animal subject to s. 173.23 (1m) if, within 7 days after custody is taken of the animal, it is not claimed by and returned to its owner under s. 173.23 (1), except that an animal taken into custody under s. 173.13 (1) (a) 3. or 4. may not be treated as unclaimed if its owner files a petition under s. 173.22 (1) within 7 days after custody is taken.

   (3)   If an animal is taken into custody under s. 173.13 (1) (a) 3., 4., or 9. and also taken into custody under s. 173.13 (1) (a) 1., only sub. (1) applies to that animal.