Veterinarians agree that dogs often eat dirt because of mineral deficiencies, boredom, behavioral problems or simply because they like the taste. Some working or very active dogs don't get enough minerals in their diet and eat dirt to compensate. A dog with behavior problems often eats dirt along with displaying other types of strange behaviors. Some dogs simply want to stay busy or like the taste of local soil.
Eating a small amount of dirt is normal and cannot harm a dog. However, if the dog is eating excessive amounts of dirt on a regular basis, it can be dangerous to the dog's health. Dirt contains small rocks and other particles that, if consumed in excess, can cause serious digestive problems and form blockages that require surgical removal. Likewise, grinding teeth by chewing and biting down on the extra rocks or particles can cause chipping and lead to infection. Some soils contain chemicals that are harmful if ingested in large amounts. If the dog has ingested enough dirt containing chemicals, it can cause serious health problems and require medical attention. If a dog has a habit of eating large amounts of dirt on a regular basis, it is important to train the dog to stop.