Snow covers scent in a very efficient way. Therefore it is amazing that Briz can feel the smell of the field mice under some 1 feet of snow that we have right now. The snow at this time of the year consists of many layers. The layers are compressed and should form a "scent proof" roof preventing any scent to pour up to the surface from the layer between soil and dead grass where the mice live. Still, when we observe Briz moving over the field we can clearly recognize when she feels the scent of a fresh field mouse.
Since she does not have the hunting technique of the wild red fox she cannot catch them. Anyway it is amazing to observe the olfactory power of a birddog! Some years ago an Irish setter bitch visited Foxy several times during the snow period and they had a lot of fun trying to dig out the mice together. When the snow melts in the spring you can see the impressive network of tunnels the mice have all over the field. They are pretty safe there during the winter.