Dear Pet Docs,

Please answer this quickly as we have to make a decision soon. Our Bullmastiff puppy is 11 weeks old. We have had her for 2 weeks.

From day one she would vomit shortly after meals. We took her to our veterinarian, who said she had a problem with her esophagus, known as mega-esophagus. He said that this could be due to a stricture, that she was born with. He fed her food mixed with a dye and took an X-ray, and said that that confirmed his suspicions.

We were told that surgery is the only treatment, but that the prognosis is not good. We want to try, but don't want to put her through an unnecessary procedure. What would you advise.

A: What you are describing is a known as a vascular ring anomaly. As a mammalian embryo develops, it has 5, paired, aortic arches in front of the heart. Abnormal development can lead to six different conditions, all known as vascular ring anomalies.

In these situations, the abnormal vessel entraps the esophagus as it passes the heart. Liquids can usually pass, but solid foods are trapped. This causes the food to accumulate in the esophagus, just in front of the vascular ring. If prolonged, this can lead to severe distension of the esophagus and result in permanent loss of function.

The first thing an owner typically sees is regurgitation shortly after feeding. Unlike vomiting, regurgitation is not accompanied by any real effort. The food just quickly comes up with no heaving. It appears undigested. Regurgitation indicates the problem is in the esophagus, not the stomach or intestines.

If this continues, untreated, the puppy will become debilitated by malnutrition, and is at high risk for development of aspiration pneumonia.

The problem first becomes apparent at the time of weaning. Ninety-five percent of the time the anomaly is due to a condition known as a persistent right aortic arch (PRAA). This has been reported in horses, cattle, cats and dogs. German shepherds and Irish setters are among the most commonly affected breeds. The condition can usually be defined by an X-ray. Occasionally more sophisticated imaging is necessary. Once the diagnosis is made, surgery should be performed as soon as possible, provided the patient is stable and fit for anesthesia and surgery. This is to minimize irreversible damage to the esophagus, and reduce the risk of aspiration pneumonia.

The treatment involves an "open chest" procedure, and it is risky. Reported survival rates are about 80 percent. This may sound like good odds, but it means one in five will not make it through surgery. Some big reasons for the relatively high mortality rate are that these are puppies, and they are often debilitated by malnutrition prior to surgery, or develop pneumonia afterwards.

For many years, there was a gap between the reported outcomes, and what many surgeons believed about how well these patients did. Sadly, these pessimistic reports led to a widespread belief that surgery was ineffective, and many dogs were euthanized as a result. In 1997, a report was published that supported what many surgeons already thought, which was that of the patients who made it through surgery, most were vastly improved. Ninety percent of patients have good to excellent outcomes. They no longer regurgitate or only do so sporadically. And their body condition significantly improves. Only about 10 percent failed to respond at all to surgery. The biggest hurdle, is surviving the procedure.

So, the odds are certainly in your favor and this is a procedure that's best done early. So find a qualified surgeon and go for it. Good luck!

Dr. Henri Bianucci and Dr. Perry Jameson are with Veterinary Specialty Care LLC. Send questions to petdocs@postandcourier.com or veterinaryspecialtycare.com.