We encountered a poisonous "viper" snake in our woods and several other dog owners who let their dogs run loose have encountered them already.
http://en.wikipedia.org/wiki/File:Viper ... Szczepanek).jpg
Here is a website that shows a few photos of what they look like.
http://www.sammakkolampi.fi/lajit/kyy.html
If bitten a quick trip to the doctor or vet is a must. These are all over the Scandinavian woods in summer. So have to be very careful while in the woods or camp areas.
Here is a site in English. http://en.wikipedia.org/wiki/Vipera_berus
Classic Finn