Comparative anatomy of feline and canine gastric sling fibers

Investigation of the function of human sling fibers is not feasible with the use of technics currently available for animal experiments. Thus, this study examined the anatomy of the gastric sling fibers in 22 dogs and 16 cats to determine if either or both resemble that of the human. In both species, the gastric sling fibers hooked around the notch between the gastric fundus and distal esophagus, and traversed the stomach, anteriorly and posteriorly, parallel to the lesser curve, finally disappearing near the incisura angularis. A constrictor cardiac muscle was found at the upper limit of the sling fibers in both species. The muscularis propria of the distal esophagus of the dog was found to be striated. In contrast, smooth muscle was present in the distal esophagus of the cat. Furthermore, a vestibule, analogous to that described in man, was found in the cat but not in the dog. It has been postulated that the sling fibers play a role in the sphincteric mechanism of the distal esophagus. Our finding that the anatomy of the sling fibers and the distal esophagus in the cat resembles that of man suggests that it would be a more suitable model than that of the dog.