Euthanizer tells the story of a mechanic who euthanises sick and old pets as a side job. Despite the grim work, he has a soft spot for the animals. Trouble stirs when the owner of a dog he was supposed to end realises that the canine is still alive. The only innocent party in the drama that ensues is the dog itself.

Summer 1962 and Olli Mäki has a shot at the world championship title in featherweight boxing. From the Finnish countryside to the bright lights of Helsinki, everything has been prepared for his fame and fortune. All Olli has to do is lose weight and concentrate. But there is a problem – he has fallen in love with Raija.