Arriving in Sweden, travelers are divided into two groups that are treated differently by customs: Travelers arriving from within the EU, and travelers coming to Sweden from outside the European Union. Depending on which group you're in decides your duty free limits. This article also explains how to bring your pet to Sweden.
Current Finnish Customs Regulations are also easy to understand, except the detailed rules on bringing alcoholic beverages into this country. Make sure to take a look at the prescription medicine limits to avoid confiscation of your meds upon your arrival in Finland, and learn how to take your pet with you on your Finland trip.
Not being one of the EU member countries, Iceland's customs regulations currently vary quite a bit from the ones used in most of Europe. There are unexpected restrictions on some items when you arrive in Iceland, and a limit on the duty-free import/export of gifts. While you can bring pets, the procedure is long and involves quarantine. Find out more here.