Oregon Revised Statutes Animals § 596.470

Whenever any official examination is made by any person authorized so to do by the State Department of Agriculture, of any livestock and such livestock is found free from contagious, infectious and communicable disease, the person making such examination shall make and deliver to the owner or person in possession of such livestock, a certificate to that effect, under such rules and regulations and in such form as the department may prescribe. Whenever an examination or test is made as to any particular disease and the livestock is found free therefrom, a certificate of that fact shall be given to the owner.