Tennessee Code Title 44. Animals and Animal Husbandry § 44-17-304

(a) Before any public or private agency, animal shelter or other facility operated for the collection, care or euthanasia of stray, neglected, abandoned or unwanted non-livestock animals euthanizes a non-livestock animal that the facility knows or should know, by identification or vaccination tags, personal knowledge or otherwise, has an owner, the facility shall be required to hold the animal for at least three (3) full business days from the time it is brought to the facility before the animal may be euthanized.

(b) Subsection (a) shall not apply where an emergency situation exists that requires the immediate euthanasia of an injured, dangerous or severely diseased non-livestock animal.

(c) A public or private agency, animal shelter, or other facility that knows or should know that a non-livestock animal has an owner under subsection (a) must make a reasonable effort to locate and notify the animal's owners within forty-eight (48) hours of the time that the public or private agency, animal shelter, or other facility takes custody of the animal or, if the animal is taken into custody on a Friday, within two (2) business days of the date that the public or private agency, animal shelter, or other facility takes custody of the animal.