9 CFR 2.55: Removal and disposal of tags.

(a) Where a dog or cat to which is affixed or which is identified by an official tag is euthanized, or dies from other causes, the dealer or exhibitor shall remove and retain the tag for the required period, as set forth in paragraph (b) of this section.

(b) All official tags removed and retained by a dealer or exhibitor shall be held until called for by an APHIS official or for a period of 1 year.

(c) When official tags are removed from animals for disposal, the tags must be disposed of so as to preclude their reuse for animal identification. No animal identification number shall be used within any 5-year period following its previous use.