PRRA is a congenital defect in which a branch of the aorta crosses over and pinches off the lower end of the esophagus. If your dog does have PRA, the sooner he has surgery (which is quite successful) the more likely it will be that the megaesophagus will resolve itself, most likely completely.

Our pup had the surgery at a very young age (about 9 or 10 weeks, as I recall), and he’s now a happy, healthy adult. But, if we had waited to do the surgery until later, the megaesophagus might have become a permanent condition. So please have your vet rule out PRA as soon as possible.

There are many forms of Vascular Ring Anomolies, one of which is PRAA. 95% of vasc rings will be PRRA with a non patent left ligamentum arteriosum. The other 5% are either a double aortic arch, LAA and a right ductus or ligamentum, or LAA with abberant right subclavian. All of which should have a cath study before surgery.

I would think that if the puppy is getting nutrition and fluids enough to maintain growth it probably will act very normal. Once the body grows and the “band” that remains doesn’t disappear, I think that would be when the pup would start not doing well. So, in many, the symptoms occur very early, some later.

There have also been reports of “late onset” symptoms developing in older dogs: ” J Am Vet Med Assoc. 1987 Oct 15;191(8):981-3.Links Late-onset regurgitation associated with persistent right aortic arch in two dogs.

Fingeroth JM, Fossum TW.
Department of Veterinary Clinical Sciences,
Ohio State University, Columbus 43210.

Congenital persistent right aortic arch was diagnosed as the cause of weight loss and regurgitation in 2 dogs, aged 2.5 and 8 years, respectively. The first dog had 2 brief episodes of regurgitation that resolved spontaneously before the most recent onset of signs and diagnosis. The second dog had no clinical signs
attributed to persistent right aortic arch until 2 months before the diagnosis was made. Dogs born with persistent right aortic  arch typically have clinical signs of esophageal stenosis around the time of weaning. Evidence from the 2 dogs in this report indicate that clinical signs associated with vascular ring anomalies may not become evident until later in life. Veterinarians should consider the diagnosis of persistent right aortic arch in any age dog that is admitted because of regurgitation, weight loss, and dilatation of the cranial portion of the esophagus.”

And, “Journal of the American Animal Hospital
Association 44:258-261 (2008)
© 2008 American Animal Hospital Association
Case Report
Delayed Primary Surgical Treatment in a Dog
With a Persistent Right Aortic Arch
Catherine A. Loughin, DVM and Dominic J.
Marino, DVM, Diplomate ACVS, ACCT, CCRP

From the Department of Surgery, Long Island
Veterinary Specialists, 163 South Service Road,
Plainview, New York 11803.

A 5-year-old, 1.36-kg, neutered male Yorkshire terrier was referred for evaluation of a persistent right aortic arch with concurrent megaesophagus. The dog was 3 months old when clinical signs were first noted, 2 years of age when diagnosed with megaesophagus, and 4 years of age when diagnosed with vascular ring anomaly (VRA). Surgical correction of the VRA was performed when the dog was 5 years of age, after gastrostomy tube feeding for 1 year to maintain nutritional requirements and mitigate the degree and duration of the esophageal distention. Thirteen months after surgery, the dog was eating  soft dog food with no vomiting or regurgitation.”

For those of you who would like to know more: