FREEDOM OF ESTABLISHMENT - VETERINARY SURGEONS - DEGREES OBTAINED IN A MEMBER STATE - PRACTICE IN ANOTHER MEMBER STATE - CONDITIONS - PERIOD PRIOR TO THE IMPLEMENTATION OF THE DIRECTIVES FOR THE MUTUAL RECOGNITION OF DIPLOMAS AND THE CO-ORDINATION OF NATIONAL PROVISIONS ( EEC TREATY , ARTS . 52 AND 57 ; COUNCIL DIRECTIVES NOS 78/1026 AND 78/1027 )