Without prejudice to Article 23(4), with regard to nationals of Member States whose evidence of formal qualifications as a veterinary surgeon was issued by, or whose training commenced in, Estonia before 1 May 2004, Member States shall recognise such evidence of formal qualifications as a veterinary surgeon if it is accompanied by a certificate stating that such persons have effectively and lawfully been engaged in the activities in question in Estonia for at least five consecutive years during the seven years prior to the date of issue of the certificate.