Your Westie probably owns every inch of his rugged terrier heritage! Plus, as a white dog which needs to be groomed regularly, the West Highland White is prone to all sorts of skin irritations.
No matter how careful the groomer is, a hair too close with the clippers and your Westie can have what is called "clipper burn". While not an actual BURN, it is still an irritation that needs to be treated. Boo Boo Butter is made for just such issues.
No artificial ingredients, no synthetics, no petroleum by-products, nothing you cannot pronounce, just good stuff to support your Westie's healing process.