CHARACTERIZATION OF ANTERIOR SEGMENT OPHTHALMOLOGIC LESIONS IDENTIFIED IN FREE-RANGING DOLPHINS AND THOSE UNDER HUMAN CARE

Dolphin-WET-Development of a Welfare Evaluation Tool for Bottlenose Dolphins (Tursiops truncatus) under Human Care

Ensuring high standards of animal welfare is not only an ethical duty for zoos and aquariums, but it is also essential to achieve their conservation, education, and research goals. While for some species, animal welfare assessment frameworks are already in place, little has been done for marine animals under human care. Responding to this demand, the welfare committee of the European Association for Aquatic Mammals (EAAM) set up a group of experts on welfare science, cetacean biology, and zoo animal medicine across Europe. Their objective was to develop a comprehensive tool to evaluate the welfare of bottlenose dolphins (Tursiops truncatus), named Dolphin-WET. The tool encompasses 49 indicators that were either validated through peer review or management-based expertise. The first of its kind, the Dolphin-WET is a species-specific welfare assessment tool that provides a holistic approach to evaluating dolphin welfare. Inspired by Mellor's Five Domains Model and the Welfare Quality®, its hierarchical structure allows for detailed assessments from overall welfare down to specific indicators. Through combining 37 animal-based and 12 resource-based indicators that are evaluated based on a two- or three-level scoring, the protocol offers a detailed evaluation of individual dolphins. This approach allows for regular internal monitoring and targeted welfare management, enabling caretakers to address specific welfare concerns effectively.

MEASUREMENT OF INTRAOCULAR PRESSURE USING REBOUND TONOMETRY IN ANESTHETIZED PERUVIAN FUR SEALS (ARCTOCEPHALUS AUSTRALIS) FROM PUNTA SAN JUAN, PERU

Ocular disease in pinnipeds under human care is well described, and intraocular pressure (IOP) can be impacted by a variety of ophthalmic conditions. Species-specific reference parameters from clinically normal animals are instrumental for understanding how ophthalmic diseases may impact ocular pressures. IOP measurements were obtained using rebound tonometry from free-ranging Peruvian fur seals (Arctocephalus australis unnamed subspecies) at Punta San Juan, Peru, over a 6-yr period (2010-2016). Retrospective data obtained from 108 (81 adults and 27 neonates comprising 69 females and 39 males) anesthetized fur seals with normal anterior segment ophthalmic examinations was included in the analysis. Differences in IOP from each eye were compared to categorical variables (age, year, sex, restraint) using an independent-samples t test. All univariate results with a significance of P < 0.05 were included in multivariate analysis. Of the 13 general linear models evaluated, the top two for both the right and the left eye included age class when all variables were evaluated simultaneously. Neonates had significantly lower IOP values than adults in both the right eye (17.5 mm Hg; 95% confidence interval [CI]: 14.0-21.1 mm Hg compared to 33.5 mm Hg; 95% CI: 31.0-36.1 mm Hg, respectively) and the left eye (18.4 mm Hg; 95% CI: 14.4-22.5 mm Hg compared to 32.3 mm Hg; 95% CI: 29.3-35.3 mm Hg, respectively). Anesthesia method was not statistically significant (P > 0.05). This is the first report of normal IOP measurements for any fur seal species. Described data can be used to improve diagnosis and management of ocular alterations in pinnipeds.

SURVEY OF CLINICAL OPHTHALMIC DISEASE IN THE GIANT PANDA (AILUROPODA MELANOLEUCA) AMONG NORTH AMERICAN ZOOLOGICAL INSTITUTIONS

This study surveyed six North American zoologic institutions to collect retrospective information on the incidence of ocular disease in the giant panda. Reported information included sex and age at presentation, as well as diagnosis, treatment, duration, and clinical outcome for each episode of ocular disease. Among the 42 animals included in the survey, 10 (23.8%) had clinical ocular abnormalities reported. Multiple disease episodes were reported in four animals, with 20 clinical episodes, and one additional animal who presented with corneal scarring from historic keratitis. Age at presentation varied from 0.4 to 26 yr (mean, 11.8 yr; median, 10.4 yr). Corneal abnormalities (including corneal opacity or haze, keratitis, corneal ulcers, and bullous keratopathy) were the most common pathologies reported, followed by conjunctivitis and/or ocular discharge. Additional reported abnormalities included limbal squamous cell carcinoma and lipid degeneration. Six cases resolved without intervention. Treatment protocols included topical and/or systemic medication with or without surgical intervention, which commonly resulted in resolution with or without persistent corneal scar. The prevalence of ocular disease identified in the giant panda in this study is higher than previous publications surveying ocular disease in the family Ursidae, indicating that this is an important source of morbidity in this species.

Ocular Surface Diseases in Marine Mammals

Marine mammal eyes are adapted for underwater and air environments by increasing the mucins in tear film and having flatter corneas and round crystalline lenses. The cornea and lens are most commonly affected by environmental imbalances. Lack of shade and excessive exposure to sunlight are significant risk factors for keratopathy in pinnipeds, and likely true in cetaceans. Natural aging is also important, as sun damage and exposure to other oxidative stressors can cause cumulative damage to the cornea over time. By diminishing UV exposure and optimizing environmental factors, surface ocular disease in marine mammals can be diminished.

Clinical management of Candida albicans keratomycosis in a bottlenose dolphin (Tursiops truncatus)

OBJECTIVE

Corneal ulceration secondary to trauma commonly affects marine mammals, often with opportunistic secondary bacterial or fungal infections. This report characterizes the combined use of auriculopalpebral and ophthalmic nerve blocks, adipose-derived stem cells, and subconjunctival injections for successful treatment of corneal trauma and infection in dolphins.

ANIMAL STUDIED

An 11-year-old, female bottlenose dolphin (Tursiops truncatus) presented with bilateral diffuse corneal opacities, which progressed to keratomycosis caused by Candida albicans.

PROCEDURE

Aggressive medical management was employed, including the use of subconjunctival injections of adipose-derived stem cells, plasma, topical and oral antifungals and antibiotics, and anti-inflammatory and pain medications. Anesthetic block of the auriculopalpebral and ophthalmic nerves was employed to evaluate the corneas.

CONCLUSION

Subconjunctival injections were employed over 52 days, followed by topical drops for 5 months. At last evaluation, there was no evidence of blepharospasm bilaterally. Only a faint superficial gray corneal opacity remained OS. A temporal paraxial corneal opacity was present OD, with receding inactive vascularization and a small amount of melanosis temporally.