N.C. Gen. Stat. § 68-20
If the owner fails to redeem his livestock within three days after the notice and demand as provided in G.S. 68-18 is received or within three days after the determination of the costs and damages as provided in G.S. 68-19, the impounder shall notify the local Sheriff's office and the Sheriff shall post a notice fully describing the livestock and stating the place, date, and hour of sale on the Web site of the Sheriff's office. After 10 days from such posting, the impounder shall sell the livestock at public auction. If the owner of the livestock remains unknown to the impounder, then, three days after publication of the notice required by G.S. 68-18.1, the impounder shall notify the local Sheriff's office and the Sheriff shall post a notice fully describing the livestock and stating the place, date, and hour of sale on the Web site of the Sheriff's office. After 10 days from such posting, the impounder shall sell the livestock at public auction. The proceeds of any such public sale shall be applied to pay the reasonable costs of impounding and maintaining the livestock and the damages to the impounder caused by the livestock. Reasonable costs of impounding shall include any fees paid pursuant to G.S. 68-18.1 in an attempt to locate the owner of the livestock. The balance, if any, shall be paid to the owner of the livestock, if known, or, if the owner is not known, then to the school fund of the county where the livestock was impounded.
N.C. Gen. Stat. § 68-20