Morphological and histological study of the third eyelid in hedgehogs

The third eyelid in animals plays an important role in maintaining eye health. Like other organs of the body, the third eyelid can be afflicted with minor or deep injuries, inflammations or even tumours in different species.

The current study investigates the morphological and histological characteristics of the third eyelid in hedgehogs.

Eight healthy adult hedgehogs (male and female) weighing 500-700 g were included in this study. Deceased animals were used for this study. Few incisions were applied around the eye and eye socket. The eye was removed, and the samples were fixated in 10% formalin solution to prepare for the histological study. To evaluate the morphological characteristics, the third eyelid was placed in 2% and 4% formalin solutions.

The histological study revealed that the third eyelid cartilage is an elastic cartilage and includes chondroblasts and chondrocytes. The cells of this cartilage were either distributed individually or in isogenic groups. The bulbar and palpebral surfaces of the eyelids were devoid of any glands and were covered with a non-keratinized stratified squamous epithelium. The anatomical examination also showed that the third eyelid had an oval-shaped cartilage.

Comparing the results of this study with reports on other rodents showed that the morphological and histological structure of the cartilage in the hedgehog's third eyelid is mostly like the structure of this tissue in Indian mongoose (Herpestes javanicus).