A black spot on your dog’s tooth can indicate a few potential issues, and it’s important to have a veterinarian assess it to determine the exact cause. Here are some common reasons for black spots on a dog’s tooth:

1. Tooth Decay (Cavities): Just like in humans, dogs can develop cavities, which may appear as black spots on the teeth. This is often due to bacteria and food debris accumulating on the tooth surface.
2. Enamel Defects: Some dogs have enamel defects that cause discoloration, including black spots. This can be due to genetics or early-life illness.
3. Dental Trauma: If your dog has injured its tooth, the damage could result in a black or dark spot. Trauma can cause the tooth to die, leading to discoloration.
4. Tartar Build-up: Sometimes, a black spot is just a result of tartar buildup, which can easily be cleaned by a professional during a dental cleaning.