They originate from herds: ... (ii) in which, immediately prior to the isolation period referred to in subparagraph 6, no evidence has been recorded which leads to a conclusion that - anthrax, has occured during the previous 30 days, - rabies, Aujeszky's disease, swine dysentery, viral encephalomyelitis (vomiting-and-wasting disease), leptospirosis and atrophic rhinitis have occured during the previous six months, - transmissible gastroenteritis and swine influenza have occured during the previous 12 months ...