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Pyloric Stenosis and Pylorospasm

The dog's stomach is a sac-like structure designed to store large volumes of food and begin the digestive process. Once eaten, most food leaves the stomach within twelve hours after entering. The esophagus carries food to the stomach, where it enters via a valve-like structure called the cardiac sphincter. On the interior surface of the stomach is a series of folds called gastric folds. These folds function to help grind and digest food. The inner stomach lining secretes acids and enzymes to break food down as the initial step in the digestive process. Once the initial stomach digestive process is complete, the partially digested food exits the stomach through the pyloric sphincter area and then enters the duodenum (small intestine).

Where the stomach empties into the duodenum, there is a circular valve-like muscle called the pyloric sphincter. The pyloric sphincter constricts and dilates to regulate the flow of food from the stomach into the small intestine. Occasionally, for unknown reasons, the pyloric sphincter constricts or spasms, causing an abnormal narrowing (stenosis) of the entrance into the small intestine. Small breeds, especially nervous individuals, seem to develop this condition more frequently than others.

What are the symptoms?
Intermittent vomiting within one to two hours of eating is the most common sign of pyloric stenosis. The food will appear undigested, pretty much looking just as it did when eaten. The sphincter may not always be constricting or spastic, therefore, some meals may pass without vomiting. Additionally, liquid diets or water will pass through the narrowed sphincter more easily than bulky foods. In severe cases, weight loss may develop.

What are the risks?
Many dogs live normal lives with only occasional episodes of vomiting. It appears the muscular spasms are not always constant in these cases. If a dog is exhibiting severe stomach outflow restrictions from a more constant pyloric stenosis, then weight loss and even death can result.

What is the management?
A diagnosis is not always easy. A careful history of vomiting in relation to eating must be evaluated. Barium studies with radiographs (X-rays) may reveal the narrowed stomach outflow. Once diagnosed, surgery provides the best cure. The pyloric sphincter, being a narrow muscular band, can be surgically severed, thus eliminating the constriction. Additionally, the stomach outflow area can be surgically widened, allowing food to pass into the duodenum. The outcome after surgery is excellent.

General Information

The pylorus is the short muscular passage between the stomach and the small intestine. Normally it remains closed, allowing the stomach to fill with food; then it opens in rhythm with the stomach contractions, allowing food to pass into the small intestine.

In pylorospasm, the muscle fails to relax and allow food to pass from the stomach. This results in vomiting of undigested food. Pyloric stenosis is a narrowing of the pylorus. This condition also interferes with the passage of food from the stomach, and vomiting is the usual result. Pyloric stenosis may be present since birth (congenital) or the result of chronic infection, untreated pylorospasm, or a tumor of the pylorus. Radiographs (x-rays) or exploratory surgery may be required to reach a final diagnosis.


Your pet has: ______________________________________________________________

Important Points in Treatment

1. Pylorospasm is treated by dietary control, medication to prevent spasm, and occasionally tranquilizers. Chances for control and possible cure are very good; however, prolonged treatment may be necessary.

2. Pyloric stenosis is treated by surgery to enlarge the pylorus. If the condition is congenital, the chances for cure are excellent. If it is due to other causes, chance for complete cure are fair.

3. Diet: Follow the instructions checked.

____Feed the normal diet.

____A special diet is required. Feed as follows: ______________________________________


4. Postsurgical care:

Check the incision daily. Report any abnormalities to the doctor.

Give medication as directed. Call the doctor if you cannot give the medication.

5. Activity: Follow the instructions checked.

____Allow normal activity.

____Restrict activity as follows: ___________________________________________________


Notify the Doctor if Any of the Following Occur:

* Your pet appears depressed or refuses to eat.

* Your pet vomits or has blood in the stool.

* Your pet removes the sutures or otherwise damages the incision.

* There is a change in your pet's general health.