Morfologia do bulbo do olho e anexos de tamanduá-mirim (tamandua tetradactyla).

Abstract

The anatomy of the eyeball and adnexa has been described in several domestic animal species. However, in wild animals, few studies are available, which may negatively impact clinical and surgical decision-making. The aim of this study was to describe the anatomical characteristics of the eyeball and adnexa in the southern tamandua (Tamandua tetradactyla). Ten cadavers of southern tamanduas, donated to the Veterinary Anatomy Sector of EMEVZ after death, were included in this study. Analyses were performed through topographic dissection, exenteration, and ocular ultrasonography. The results show that the eyeball of the southern tamandua is small compared with that of domestic species. Regarding the adnexa, two dorsal rectus muscles, one lateral rectus, one medial rectus, and one ventral rectus were identified, in addition to the ventral oblique and the retractor bulbi muscles. The dorsal oblique muscle was absent. The lacrimal gland is small, dorsolateral to the eyeball, and a well-developed, lobulated gland with a continuous peripheral arrangement around the eyeball, adapting to the scleral contour, was observed, with morphology similar to the Harderian gland. It is concluded that the ocular anatomy of the southern tamandua resembles that of domestic species; however, it presents distinct features, such as the absence of the dorsal oblique muscle, the presence of a structure suggestive of the Harderian gland, and the duplication of the dorsal rectus muscle.