I'm so glad you asked this question! I love Scotties and have had the pleasure of owning four over the years (although I should probably note that the Scotties have actually owned me since that is their nature). My current Scottie is Maisie.
I would suggest searching for Mary Engelbreit stamps of "Henry", a Scottish Terrier. The following link should show you two of these stamps. I own the one with Henry wearing the polka dotted sweater. So cute!
Scottie Dog - Mary Engelbreit
Megan