Persistent Right Aortic
What is a persistent right aortic arch?
This is actually
a vascular abnormality that results in constriction of the oesophagus over
the base of the heart, causing a build up of food forward of the obstruction.
Signs are regurgitation of solid foods almost immediately after eating
(seen from 3-4 weeks of age). These are diagnosed by their very characteristic
appearance on barium X ray. In this type of abnormality, the actual musculature
of the oesophagus is normal. Praa can be corrected surgically
(usually not before 12-14 weeks of age), however as the operation is intra-thoracic,
the puppy usually has to be of a reasonable size and weight before operation.
The prognosis can be guarded as the puppies are often thin, undersized and
there can be secondary pneumonia. Most improve dramatically after the
operation, however some can persist in having some dilatation in the 1st 1/3
of the oesophagus. Feeding of these puppies is by giving them a more liquid
diet and feeding them with the food in an elevated position so as to provide
a straighter passage through the chest to the stomach.
The term vascular ring anomaly describes several disorders that
occur because of abnormal development of the blood vessels that arise
from the aortic arch in the fetus. The most common abnormality is a persistent
right aortic arch which develops instead of the left aortic arch that would
normally become the permanent aorta, the main blood vessel leading from
Click to see enlarged image
These anomalies are relatively common in dogs. They do not cause
cardiovascular problems; however the abnormal blood vessel forms a ring
which entraps the esophagus and sometimes the trachea, causing regurgitation,
unthriftiness, and often aspiration pneumonia.
How is a persistent right aortic arch inherited?
Inheritance is complex.
What breeds are affected by persistent right aortic arch?
There is an increased incidence of this disorder in the Great Dane,
German Shepherd and Irish setter, relative to other breeds.
What does a persistent right aortic arch mean to your dog &
Signs associated with entrapment of the esophagus usually become
apparent shortly after weaning, when the dog begins eating semi-solid
or solid food. The partial obstruction of the esophagus causes regurgitation
and, over time, dilation of the esophagus ahead of the obstructed area.
Dogs with this condition are thin, may be malnourished and have ravenous
appetites. They are prone to aspiration pneumonia.
These anomalies can be corrected surgically. It is important to
do so before there is permanent damage to the esophagus.
How is a persistent right aortic arch diagnosed?
In a dog that begins regurgitating shortly after weaning, this
condition is suspected. Chest x-rays will confirm this, in particular
a contrast study with barium which will show the dilated esophagus just
ahead of the obstruction, located at the base of the heart. It is important
to differentiate this condition from megaesophagus, which causes similar
signs and in which the esophagus is dilated throughout its length.
How is a persistent right aortic arch treated?
Treatment is surgical. The constricting ring is separated. Surgery
should be performed early, before permanent damage has occurred to the
lining of the esophagus due to distension.
Postoperative care involves feeding a liquid diet with gradual
introduction of frequent small meals. In some dogs occasional regurgitation
Affected individuals and their parents should not be used for breeding.
Siblings should only be used after careful screening. If any affected
offspring are born, breeding of the parents should be discontinued.
FOR MORE INFORMATION ABOUT THIS DISORDER, PLEASE SEE YOUR VETERINARIAN.
Patterson, D.F. 1996. The genetics of canine congenital heart
disease. ACVIM-Proceedings of the 14th Annual Veterinary Medical
Forum: 225-226. This reference has good information for breeders
and veterinarians regarding screening and genetic counselling for congenital
This database is funded jointly by the
Animal Welfare Unit at the Atlantic Veterinary College, University of Prince
Edward Island, and the Canadian Veterinary Medical Association.
Copyright © 1998 Canine Inherited
Disorders Database. All rights reserved. Revised: October
with kind permission from:-
Crook, DVM,Coordinator, Sir James Dunn Animal Welfare Centre, Atlantic
Veterinary College,University of Prince Edward Island, 550 University
Ave.Charlottetown, PEI C1A 4P3
The above information is simply informational.
It's intent is not to replace the advice of a veterinarian nor to assist
you in making a diagnosis of your pet. Please consult with your own veterinarian
for confirmation of any diagnosis. Your pets life may depend on it.