Postnatal developmental Histomorphological and histochemical study of the duodenum in the domestic cat (Felis Catus)

The present study was conducted to investigates the histomorphological and histochemical developmental changes established in the duodenum of the domestic cats at three different postnatal ages, that were one week (suckling kittens), 4-6 weeks (weaned immature cats) and adult of one year and up cats. Macromorphometric measurements of duodenum were conducted and listed in tables. Histological sections prepared and stained by general and special stains. Gross findings revealed that the duodenum is U-shaped of longer descending part and shorter ascending part. The beginning of the duodenum contains duodenal papilla in which found central orifice for the exits of bile and pancreatic secretions. The internal mucosal surface of the organ showed gross circular folds called plicae circularis. Histologically, the wall of duodenum in suckling kittens possessed thick tunica muscularis and thin mucosa, but it changed in weaned immature and adult cats to become thin tunica muscularis and thick mucosa. At all ages the submucosa remains thin layer, but slightly thickened in the first part of descending duodenum due to the presence of Brunner's glands. Characteristically goblet cells in cat's duodenum were rounded or circular in shape rather than globular shape as usually found. Their number in the villi was higher than those counted in the duodenal crypts at one week, but approximately equal in number in the 4 weeks and were conversely changed in adult in which the percentage of goblet cells was higher in crypts than in the villi. Histochemically they were stained faintly with PAS stain showed moderate amount of neutral mucin in their cytoplasm. Paneth cells were detected in the duodenal crypts in 4 weeks aged cats and subsequent adult cat but not after birth in one week aged kittens. It could be concluded that the duodenum was not fully developed in cats at birth.