Consistent postprandial regurgitation in young dogs also can be caused by various other congenital and acquired abnormalities that must be differentiated from PRAA. Most common are foreign bodies and megaesophagus but others include an overly long esophagus, esophageal stricture, and horizontal heart.

Often, a simple DV or VD survey radiograph provides a reliable diagnostic sign of PRAA: moderate to marked leftward curvature of the trachea near the cranial border of the heart was found in 27/27 dogs with PRAA and in none of 63 control dogs or 30 dogs with megaesophagus. Barium esophagrams sometimes obscure this sign.

RIGHTWARD			Straight	LEFTWARD
marked	mod	mild	midline	mild	mod	marked
7	20	38	27	1	7	20
(63 control dogs+ 30 with megasophagus)				(27/27 PRAA)

Incomplete barium esophagrams in 2 dogs with megaesophagus were misinterpreted as evidence of vascular rings and led to inappropriate surgery. Retrospective evaluation of the esophagram in each dog revealed separation (S) of the esophagus and trachea, which is unlikely to occur in a dog with a vascular ring. Fluoroscopy should be done if tracheal position is not visible in a DV or VD radiograph.

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Barium esophagram and surgery photograph of a dog with overly long esophagus.

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Barium esophagram of a dog with esophageal stricture. The stricture is located caudal to the heart and the site of vascular rings.

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A horizontally-oriented heart with a transverse left aortic arch in a beagle allowed the esophagus to droop ventrally between the brachiocephalic trunk and the left subclavian artery. Regurgitation was relieved by dividing the left subclavian. This condition also has been reported in English bulldogs.

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