The commission and its agents, employees, livestock law enforcement officers, and livestock inspectors may visit all sections of this State where contagious, infectious, or communicable disease among animals including poultry and domesticated fowl is believed to exist and shall determine according to law whether affected animals are worthy of remedial treatment or, considering the animal industry, must be destroyed. The commission shall conduct scheduled and unscheduled inspections of premises operating under permit issued by him and conduct solely or in conjunction with other appropriate agencies necessary investigations involving matters assigned by law to its jurisdiction.