Discipline: Veterinary Medicine
The histology and some histochemical features and morphometrics of the nasolabial glands of the Philippine water buffalo and cattle were described and compared using sections stained with hematoxylin and eosin (H & E), periodic acid-Schiff (PAS) and alcian blue (AB) pH 1.0. In both species well-developed nasolabial glands were found in the hypodermis of the muzzle. In the Philippine water buffalo, however, the glands may extend into the reticular layer of the dermis. The histomorphology of the nasolabial glands were basically similar in both species except that in the Philippine water buffalo the lobules were more distinct because of thicker interlobular connective tissue septae. Intralobular and intralobar ducts were also more numerous in Philippine water buffaloes. Slightly coiled and straight excretory ducts were observed in both species. Based on the type of secretion, the nasolabial glands in both species were predominantly mucous. The reactions of the secretory acini to the PAS and AB pH 1.0 stains were identical in both species. Morphometrically, the only significant difference observed between the two species was on the height of the intralobular duct epithelium. The intralobular duct epithelium was highest in male Philippine water buffaloes and lowest in female Philippine water buffaloes.