What Damage Can Rocks Do in a Dog's Stomach?

Of course your dog enjoys a nice treat every now and then, but rocks? Even though they're tasteless and potentially tooth-shattering, some dogs gnaw on rocks every now and then. If it's a small rock, it's likely to be no problem. However if it's too large to exit his stomach, he risks dehydration, vomiting and peritonitis.

Food vs. Foreign Objects

When all is well in your dog's gastrointestinal tract, food travels down his esophagus to his stomach, where it waits for approximately 12 hours before passing through his pyloric sphincter to his small intestine. However, when it's not food making the journey in and out of your dog, but instead is a rock or other foreign object, it's often not so simple. If the rock is small, it usually will pass through his digestive tract with no harm. However, if it's too large to exit his stomach or other part of his digestive tract he can become seriously ill.

Stuck in the Stomach

Your dog was able to swallow that rock because his esophagus can expand to accommodate pieces of food -- and objects -- that are larger than his stomach outlet. His stomach grinds and partially digests food, something it can't do to rocks and other nonfood items, which can become lodged in the stomach outflow. When a dog's stomach is obstructed with a foreign object, he'll probably vomit. Typically, if the rock or object is small, the dog will vomit intermittently -- potentially as little as once or twice a week. The larger the rock is, the more frequently the dog tends to vomit. PetEducation.com notes that a golf ball-sized object can cause a dog to vomit 20 times a day. If the dog's stomach outlet is completely blocked, he won't be able to keep anything down and will throw up everything he ingests.

Potential Dangers

A rock or any other foreign object obstructing a dog's stomach can be a life-threatening situation. Ongoing vomiting can cause dehydration and weakness and the impact the rock has on the body may be critical. Left alone, a foreign object can cause ulceration in the stomach, potentially leading to the life-threatening condition peritonitis, an inflammation of the abdominal lining that can lead to sepsis, a bloodstream infection. If the rock exerts too much pressure in the stomach, it can affect blood circulation to the organ's tissue, causing the tissue to die. As tissue dies, it releases toxic enzymes into the bloodstream, causing shock and peritonitis.

Treatment and Outcome

If the rock is too large to pass beyond the dog's stomach and make its way through the rest of the digestive tract, it must be removed. In some cases, the rock may be removed by going through the esophagus to the top of the stomach with a flexible endoscope. Usually, the dog must undergo a gastrotomy, or an opening of the stomach, to remove the rock. After recovery time and treatment to address any effects of the obstruction, most dogs have a favorable prognosis for recovering from a stomach obstruction. The vet will evaluate the dog for indications of stomach leakage for several days and administer fluids and antibiotics as necessary.

Preventing Obstructions

If your dog has an affinity for rocks, limit his access to them. You may need to contain him in a small area away from rocks when you're outside with him, or keep him on leash so you can reign him in when he spies a tempting rock. If your dog is eating more than rocks, he may have a condition known as pica, a disorder compelling a dog to eat nonfood items. A vet can help determine if it's a nutrition-related condition or if it's something that requires the help of a behaviorist or extra precautions at home.