Any person who intentionally interferes with or hinders the work of the commissioner or his agents; or who attempts to defeat the object of a test by a previous injection of tuberculin or any other drug, known as plugging; or who in any other way attempts to prevent an accurate and truthful determination of the condition of the animal tested; or who shall treat any animal with material or substance to prevent normal reaction, except for experimental purposes and with the consent of the commissioner, shall be guilty of a misdemeanor. Each such treatment shall constitute a separate offense.