Second, our animal friends rarely eat sugary or acidic foods that the bacteria that cause cavities use to create the acids that destroy our teeth. Finally, they don't live as long as we do, which decrease the time available for the bacteria to work. The most common area is on the occlusal surface of the upper first molar. In addition, you can see them on the other upper molars, the back of the upper incisors, or anywhere else. The breed that is most affected is the German shepherd dog, although any breed can develop them.
Bacterial caries appear as dark brown to black discoloration on an area of tooth surface.
Dentinal staining secondary to wear can appear like this as well, although it tends to be lighter in shade. The way to tell the difference is by feel. A sharp explorer when placed into a cavity will stick and resist removal. A worn area typically will not allow sticking at all. Wear spots that do not involve the root canal are generally not treated.