Craft Edge

I have a picture of a dog . The picture is a drawing of a Yorkie dog and the background is white, I went to You tube to watch the inscape tut on who to remove the background by tracing out the picture but he lost me after that. My problem is I can covert the jpeg or bmp into svg and open it into SCAL but when it cuts it its cuts the whole square I want to know if their is an easy way I can remove everything but the picture of the dog and put that into SCAL and have it just cut out the dog ?

Any help would be appreciated.

Dalla