If importing a PUPPY to Sweden from the UK it should NOT be rabies vaccinated as it will delay things. There is no minimum age given but it must be less than 3 months old. It will still need a pets passport with everything detailed in but NO rabies vacc. The buyer has to apply for an import licence. The puppy must be wormed for tapeworm and have a heath certificate from a vet, and must be flown directly to Sweden, cannot enter any other way. (It says boat as well but there is no ferry going directly to Sweden from the UK.) The customs must be informed. Get your puppy buyer to read this page (it is in Swedish): http://www.sjv.se/amnesomraden/djurveterinar/inutforselavlevandedjur/inochutforselavhundochkatt/atervanda/forainenvalpkattunge.4.1a84b3810dc68241ce80004713.html