Puppy Lacks Brown Eye Pigment. Flat brown spots of pigment on the sclera are normal. The brown spot in your dog’s eye could be a natural pigmentation that occurs with specific breeds or due to old age.

It is not a specific disease; When the eye is mildly affected you will see grey discoloration and brown discoloration beginning at the inside of the cornea and see that it has progressed to the center of the cornea. When vitiligo sets in in a dog, it will affect the skin around the nose making it go white or pink.