The teeth are living tissue and are covered with enamel, the hardest substance in the dog's body. Dentine is the next layer, and the core is called the pulp. The pulp contains blood vessels and nerves which nourish the teeth.
Any variation from normal tooth color is discoloration. Teeth discoloration is any variation from normal tooth color. However, the normal color of teeth varies, dependent on the shade, thickness, and translucency of the enamel covering the tooth.
Discoloration can be categorized into Extrinsic and Intrinsic discoloration. Extrinsic discoloration is due to an external cause. It occurs when exogenous pigments accumulate on the surface of the teeth where as intrinsic discoloration occurs due to secondary factors that are heppening inside the tooth, discoloring the underlying dentine.
Common symptoms associated with both discoloration types include:
Abnormal coloration of one or more teeth
Pitted enamel (the glossy covering of the tooth) with staining
Rings or lines of discoloration around one or more teeth