Discipline: Veterinary Medicine
The gross, histological and histochemical features of the lacrimal gland of the Philippine water buffalo were described. The lacrimal gland of the Philippine water buffalo was flattened and situated along the dorsolateral aspect of the eyeball . It was enclosed by the periorbita, distinctly lobulated, and pink to red in color. Its orbital surface was convex. The capsule composed chiefly of collagen fibers, detached connective tissue septa which divided the gland into lobules of various sizes. Profiles of interlobular and blood vessels were found in the connective tissue septa. The interlobular ducts in the interlobular connective tissue septum were lined by tall simple to stratified columnar epithelium. Each lobule was made up of several round to oval-shaped secretory acini. Each acinus was composed of several secretory columnar cells arranged radially around a relatively small lumen. A few basally located myoepithelial cells were observed. Distributed among the secretory acini were intercalated and intralobular ducts. Majority of the secrelery acini reacted strongly to the mucicarmine, periodic acid Schiff and alcian blue pH 2.5 stains. However, only a weak reaction was observed with alcian blue pH 1.0 stain. The duels reacted negatively to the special tissue stains. The secretory acini of the female Philippine water buffaloes showed stronger reaction to the Mayer's mucicarmine, periodic acid Schiff and alcian blue pH 2.5 than those of the male Philippine water buffaloes. Based on the microscopic features observed in the hematoxylin and eosin stained sections and the reactions to the various special stains, the lacrimal gland of the Philippine water buffalo was a mixed but predominantly mucous compound tubuloacinar gland. The gross anatomy and histology of the lacrimal gland of the Philippine water buffalo observed in the present study are basically in agreement with what have already been reported for cattle in veterinary literature.