123 P-ISSN: 2304-3075; E-ISSN: 2305-4360 International Journal of Veterinary Science www.ijvets.com; editor@ijvets.com Research Article Study of Season-Based Histo-Morphometric Variations in Lacrimal Gland of Camel (Camelus dromedarius) Zarroug H Ibrahim 1 College of Veterinary Medicine, Sudan University of Science and Technology, P.O. Box 204, Khartoum-North, Sudan 1 Current address: College of Agriculture and Veterinary Medicine, Qassim University, KSA *Corresponding author: zarrougibrahim@hotmail.com Article History: Received: March 31, 2015 Revised: April 26, 2015 Accepted: May 03, 2015 ABSTRACT The main functions of the mammalian lacrimal secretion are to wash and moisten the anterior surface of the eyeball. The seasonal morphological changes in the lacrimal gland could be a part of the mechanism that keeps the tear film at the anterior surface of the eye of dromedary camel in balance under its hot and dry habitat. This study aimed to detect the seasonal histological and morphometric changes in the lacrimal gland of dromedary camels. The study was performed on glandular samples of 20 adult healthy camels collected during hot summer and cold winter seasons from Tambul slaughterhouse, Sudan. The histological observations showed that the gland was formed of seromucous compound tubulo-alveolar secretory units. The number of serous secretory units appeared to be increased in summer compared to those in winter in which the mucous units were increased. The morphometric measurements showed significantly (P<0.05) increased glandular volume and secretory units epithelial height with consequent non- significantly (P>0.05) decreased luminal diameter in summer compared to those in winter; non-significantly (P>0.05) increased interstitial connective tissue thickness was also observed in winter. It was concluded that the seasonal climatic variations cause structural and physiological effects on the camel lacrimal gland. Key words: Dromedary, Lachrymal gland, Morphological study INTRODUCTION The dromedary camel is an economically important animal for poor families in many developing and underdeveloped countries, including Sudan and Somalia. It is kept for providing milk, meat, wool, and for race and transport of goods and people. The dromedary camel is known to be highly adapted to its harsh environment which is characterized by high temperature, lack of feed and water, and sand storms. The lacrimal gland secretion is conducted to the eye via excretory ducts where it plays an important role in washing and moistening of the anterior part of the eyeball (Dratt, 2009; Funki et al., 2010; Zogan et al., 2012). The excessive secretions leave the eye through the lacrimal openings (puncta lacrimalia) to the lacrimal sac and nasolacrimal duct where it is thought to moisten the nasal mucosa. There are no puncta lacrimalia, either in the lower or in the upper eyelid of the camel; and hence, the lacrimal secretion is considered confined to the anterior surface of the eye (Abdalla, et al., 1970; Ibrahim et al., 2006). The lacrimal gland in most domestic mammals is compound tubulo-alveolar in structure with clusters of secretory end-pieces (Dellmann and Browun, 1981; Burkitt et al., 1999; Bacha and Bacha, 2000; Mohammadpour, 2011). The septa which divide the gland into lobes and lobules of different shapes and sizes come from a connective tissue capsule that surrounds the gland. The glandular excretory ducts which convey the secretion from the gland to the eye open into the superior conjunctiva (Sinha and Calhoun, 1966; Dellman and Browun, 1981). The morphology of the lacrimal gland has been described in the different mammalian species (Sinha and Calhoun 1966; Dellman and Browun, 1981; Mohammadpour, 2011; Kleckowska-Nawrot et al., 2013). The seasonal effect on the ocular organs has been reported in the Hardarian gland which is an orbital gland of tetrapode species that acts as accessory lacrimal gland in some animals (Minucci et al., 1990; Baccari et al., 2000; Santillo et al., 2011). Ibrahim and Abdalla (2007) studied the morphometry of camel lacrimal gland. Recently, Kleckowska-Nawrot et al. (2015) have reported the lacrimal gland morphometry of African black ostrich. However, there has been no seasonal work on the morphometry and histology of lacrimal glands in camel or in any other domestic animal in the available literature. Cite This Article as: Ibrahim ZH, 2015. Study of season-based histo-morphometric variations in lacrimal gland of camel (Camelus dromedarius). Inter J Vet Sci, 4(3): 123-126. www.ijvets.com (©2015 IJVS. All rights reserved)