Morphological characteristics of the canine and feline stomach mucosa

The stomach mucosa structure in animals belonging to Order Carnivora indicates some specific characteristics in comparison with the other mammals. Between the bases of the mucosal glands and the lamina muscularis mucosae there is an additional plate which most of the morphologists have defined as lamina subglandularis. In currently used Nomina histologica this layer is indicated as stratum compactum in carnivorous stomach mucosa. The investigation aims were to study and compare canine and feline stomach tunica mucosa characteristics as well as to measure the thickness of stratum compactum and to specify some of the certain collagen types and fibronectin compounds. Conventional and differential histological and ultrastructural methods and immuno-histochemical approaches for investigation of the canine and feline stomach samples were used. The specific organization of the carnivorous stomach wall arrangement was established. In the structure of the canine stomach mucosa, no evidence of stratum compactum was observed. The presence of stratum compactum in feline stomach mucosa was ascertained and measured. Using an immunohistochemical method very high expression of collagen type IV and fibronectin, moderate positive reaction of collagen type III, and a comparatively weakest expression of collagen types I and V in the structure of stratum compactum from cat stomach mucosa was shown. The obtained results clarify the characteristics of the stomach mucosa morphology and could be used as a basis for distinguishing the stomach wall structure of the animal species belonging to Canidae and Felidae families although they are both carnivores.