The persistent right aortic arch (PRAA) is vascular ring which is formed by the aortic arch on the right side, with ligamentum arteriosum dorsolaterally, and pulmonary artery on the left and ventrally. This ring compresses the esophagus and trachea, which leads to swallowing difficulty. This malformation is with genetic prevalence and represents error in embryogenesis of the dog. In 95% of the cases of this vascular ring anomaly, a constricting band prevents solid foods from passing to the stomach which prevents the puppy from thriving well. In the remaining 5% of cases, a bizarre anomaly of the vessels is present (double aortic arch and aberrant subclavian artery), which may be difficult to correct and may not have a good prognosis.
Signs of this condition usually become apparent shortly after weaning, when a puppy begins eating semi-solid or solid food. While milk will slide down nicely, bulky foods will “jam up” in the esophagus, leading to a stretched structure and the inability to get food down, hence the symptom known as regurgitation. Regurgitation involves the puppy producing undigested food and mucus through the mouth with no effort; the pup tilts its head down and the food and mucus simply roll out. By contrast, vomiting is an active process, meaning there are abdominal contractions (heaving) and a retching noise when food and mucus are expelled out the mouth.
Often complication of the regurgitation is aspiration pneumonia (AP), which leads to poor prognosis for the patient.
The standart therapy is surgical and is with good prognosis if there is no signs of AP. Before the surgery CBC and blood chemistry is required – WBC is important to rule out infection and the level of blood sugar should be in the reference values. The surgery can be open thoracotomy or thoracoscopy – the goal is to ligate and resect the fibrous annulus.
- Patient report
The patient is 2 months old german shepherd dog with history of vomiting after eating, according to the owners, but there is no problems with water drinking. The dog have diarrhea but is in good overall condition. When the dog sleeps there is strange noises from his neck and there is visible peristaltic waves in the level of 1-st rib.
We perform CPV/CCV/Giardia and the result was negative. The CBC and blood chemistry shows no difference from the reference values.
Then we made x-ray of the chest: pic 2
Because of the typical sign of the chest, we performed and BaSO4 examination, and this was the result:pic 3
So our diagnosis is PRAA with no signs of AP. We performed surgery on the next day – it was open thoracotomy with ligation of the annulus.
Differentiation of the fibrous ring:
It’s was administrated antibiotics, pain killers, sedatives and assisted feeding. We didn’t use thoracic tube after the surgery.
On the fourth day after the surgery, the dog was discharged. Three months after the surgery the owners still make assisted feeding, but the dog is not vomiting and is in good condition.