The Impact of Surgical Excision of the Orbital Lacrimal Gland on the Aqueous Tear Production and Ocular Surface Health in Donkeys (Equus asinus)

Effects of intratesticular injection of hypertonic mannitol and saline on the quality of donkey sperm, indicators of oxidative stress and testicular tissue pathology

OBJECTIVES

The aim of the present study was to examine donkey sperm quality after intratesticular injection of hypertonic mannitol (HM) and saline (HS).

METHODS

Randomly assigned to five treatment groups were 15 adult male donkeys: (1) Control group (no treatment), (2) Surgery group (surgical castration for testosterone control), (3) NS group (normal saline intratesticular injection), (4) HS group (hypertonic saline), and (5) HM group. We injected 20 mL per testicle. We took 5 mL blood from all donkeys before injection. Castration was performed under general anesthesia 60 days later. Samples included blood and testicular tissue. Total motility (TM), progressive motility (PM), movementy features, DNA damage, morphology, viability, and plasma membrane functionality were evaluated. Hormone analyses, histomorphometric studies and oxidative stress indices including total antioxidant capacity (TAC), glutathione peroxidase (GPx), glutathione (GSH), superoxide dismutase (SOD), malondialdehyde (MDA), and NADP+/NADPH were evaluated. Apoptosis, pyroptosis-related Bax, Caspase-1, GSDMD, and Bcl-2 expression were also assessed.

RESULTS

In HS and HM groups, testosterone, epididymal sperm count, motility, viability, and plasma membrane functionality dropped while sperm DNA damage increased. HS and HM groups had significantly lower histomorphometric parameters, TAC, GPx, SOD, GSH, and Bcl-2 gene expression. MDA, NADP+/NADPH, Bax, Caspase-1, and GSDMD gene expression were substantially higher in the HS and HM groups than in the control group.

CONCLUSIONS

Toxic effects of hypertonic saline and mannitol on reproductive parameters were seen following, hence, they might be considered as a good chemical sterilizing treatment in donkeys.

Advanced platelet-rich fibrin promotes healing of induced corneal ulcer in donkeys (Equus asinus)

Ulcerative keratitis is a common disease in horses which may cause blindness. To prevent secondary bacterial and fungal infections and promote quick re-growth of the epithelial layer, different treatment approaches have been employed. This study aimed to examine the effects of advanced platelet-rich fibrin (A-PRF) gel on the healing process of experimentally induced corneal ulcers in donkeys. Nine healthy adult donkeys were used for the study. The donkeys were divided into two groups: the control group, where no medication was applied to the corneal ulcer, and the A-PRF gel group, where A-PRF gel was applied once a day on specific days after ulcer induction. The healing process was evaluated through various examinations and analyses. The results demonstrated that the A-PRF gel group showed significant improvement in the corneal ulcer area, with epithelial and stromal regeneration. At day 35, about 60% of the A-PRF group showed negative fluorescein uptake. Additionally, fewer complications were observed during the healing process compared to the control group. In conclusion, A-PRF gel is an important and safe therapeutic option for controlling ocular surface infection and promoting corneal healing. We recommend using A-PRF gel as an alternative approach, avoiding eyelid suturing, and minimizing corneal irritation.

Anatomical, Histological and Histochemical Observations of the Eyelids and Orbital Glands in the Lowland Tapir (Tapirus terrestris Linnaeus, 1785) (Perissodactyla: Ceratomorpha)

The lowland tapir is one of four species belonging to the Tapiridae family of the Ceratomorpha suborder, similar to Rhinocerotidae. This study describes anatomy with morphometry, histology (hematoxylin and eosin, Masson-Goldner trichrome, Movat pentachrome, mucicarmine, picro-Mallory trichrome) and histochemistry (PAS, AB pH 1.0, AB pH 2.5; AB pH2.5/PAS and HDI) of the upper and lower eyelids, and superficial gland of the third eyelid with the third eyelid, deep gland of the third eyelid, and lacrimal gland. The aim of the work is to show the features of the above-mentioned structures typical only for Tapiridae, as well as to show the presence of similarities and differences between the families forming the order Perissodactyla. The eyelashes on the upper eyelid were long, while those of the lower eyelid were short and much less prominent. In the upper and lower eyelid sebaceous glands, a characteristic simple alveolar gland producing a mucus-like secretion and poorly developed tarsal glands were observed. The marginal zone of the posterior surface of the eyelids was covered by stratified columnar epithelium with 18-21 layers of nucleated cells, while the bulbar zone of these surfaces was covered by cubic multilayer epithelium with 6-11 non-keratinized layers of cells and with sparse goblet cells. In only lower eyelids, numerous lymphoid nodules, diffuse lymphocytes and high endothelial venules were observed. The superficial gland was an acinar complex which secreted mucous and contained plasma cells within the interlobular and interlobular connective tissue. The upper and lower branches of the third eyelid were the shape of a bent "caudal fin" and were composed of hyaline cartilage, and they contained conjunctiva associated lymphoid tissue (CALT). The deep gland was also an acinar complex producing a serous character and having numerous diffuse lymphocytes. The lacrimal gland was an acinar complex producing seromucous secretions and had numerous plasma cells located in the glandular interstitium. The results of our research indicate that the features of the anatomy of the eyelids and orbital region in the lowland tapir are also typical of the family Tapiridae, but also have features common to the families Equidae and Rhinocerotidae. We confirm the presence of poorly developed tarsal glands in both eyelids as well as presence of a palpebral part of the lacrimal gland in the upper eyelid, which is typical only to Tapirus terrestris.