Slight volume changes in the duck lung do not imply a fundamental change in the structure of the parenchyma.

Slight changes in lung volume have previously been reported in ducks. We studied the functional structure of the lung of the domestic duck using classical anatomical techniques as well as ultrasound monitoring to unravel the causes of such changes. Later dorsal and medioventral secondary bronchi were superficially positioned and covered with a thin transparent and collapsible membrane, internally lined with a cuboidal to squamous epithelium. The lung parenchyma was rigid, with atria well supported by septa containing smooth muscles, interparabronchial septa reinforced by collagen fibres, and blood capillaries supported by epithelial plates. On ultrasound monitoring, an outward and inward movement of the lung surface during inspiration and expiration, respectively, was evident at the region where the airways were covered by the thin membranes. The movements plausibly facilitated air movement in the lung just like the air sacs. We conclude that volume changes in the duck lung occur due to a slight morphological adaptation rather than a change in the archetypical design of the avian lung parenchyma.

Transcutaneous ultrasonographic evaluation of the air-filled equine stomach and duodenum following gastroscopy.

Gastroscopy with air insufflation was performed in 10 ponies, after which a transcutaneous ultrasound examination of the stomach and duodenum was performed immediately and at 1, 2, and 4 h postgastroscopy, and 24 h after feeding. Stomach measurements included the dorsoventral and craniocaudal dimensions, as well as the stomach depth from the skin surface and stomach wall thickness at the different time periods. Gastric wall folding was observed in one pony, becoming most distinct 2-4 h postgastroscopy. An undulating stomach wall was noted in eight other ponies postgastroscopy. These observations appeared to be a response to the deflation of the stomach as the insufflated air was released gradually. Gas was detected in the duodenum after the gastroscopy. The parameters measured were noted to be useful to evaluate the extent of stomach distension due to air or feed. The ultrasonographic appearance of the stomach can, therefore, be altered by gastroscopy and this should be borne in mind when examining horses with suspected gastric disease.