A little bit of dirt consumption is unlikely to cause any long-term serious issues. Of course, the dirt could contain bacteria, parasites, or viruses. If it’s mixed with compost, it might contain moldy food. Sometimes dirt can contain fertilizers or pesticides you don’t want your dog ingesting.
The American Kennel Club (AKC) warns that a dog that eats a large amount of dirt is at risk of an impacted intestine, which can lead to surgery.
“Depending on the dirt, dental damage or wear could also be a concern,” says veterinarian Laurie S. Coger in an article for the AKC titled Why Does My Dog Eat Dirt?
Many senior dogs already suffer from dental decay, so biting down on a hard rock or stick could cause a tooth to fracture. Or, a sharp stick could hurt the inside of a dog’s mouth. Once in the digestive tract, a stick or sharp rock can puncture a dog’s throat, intestine, or stomach.
If your dog is eating dirt, try to keep an eye on him or her and discourage the behavior by distracting your dog with a treat or toy. If your dog is small enough, you can simply lift him or her away from the snack pile.