Feasibility of transesophageal echocardiography in birds without cardiac disease

To establish a technique of transesophageal echocardiography (TEE) in birds without cardiac disease and describe the imaging planes obtained.

Validation study.

18 birds including 3 pigeons (Columbia livia), 3 barred owls (Strix varia), 2 red-tailed hawks (Buteo jamaicensis), 1 goose (Anser anser), 1 mallard duck (Anas platyrhynchos), 1 Muscovy duck (Cairina moschata), 2 brown pelicans (Pelecanus occidentalis), 2 Hispaniolan Amazon parrots (Amazona ventralis), 2 red-fronted macaws (Ara rubrogenys), and 1 military macaw (Ara militaris).

For each bird, anesthesia was induced and maintained by use of isoflurane. A pediatric, multiplane transesophageal ultrasound probe was passed into the esophagus and adjusted to the level of the heart for echocardiography. Probe positions were recorded via fluoroscopy, and associated imaging planes were described.

TEE was performed successfully in all birds except the pelicans, 1 Hispaniolan Amazon parrot, and the red-fronted macaws. Five imaging planes of the heart were consistently viewed from 3 positions of the probe (identified as caudal, middle, and cranial positions relative to the cardiac silhouette). M-mode echocardiography of the left ventricle and the aortic root was performed. Color flow and spectral Doppler ultrasonographic images of in- and outflow regions were obtained. One Hispaniolan Amazon parrot died as a result of esophageal perforation.

TEE examination of birds was feasible and provided a larger number of imaging planes with better resolution and details than those typically achieved via a transcoelomic approach. However, TEE should be performed with caution in psittacines.