Hi,
What a very cute dog. My mum has one that looks like yours. It is a Friese stabij. A Friese stabij is a Dutch dog that is used on farms to hunt for mice. Check this link: http://www.sudewyn.nl/friesestabijfotos.htm
I think yors is a Stabij (of part Stabij), and a cutie ofcourse.

Kind regards from Holland, Carlio