Ophthalmic diagnostic testing and examination findings in a colony of captive brown pelicans (Pelecanus occidentalis)

Abstract

To the author's knowledge, this is the first report of normal ophthalmic parameters and the incidence and type of ocular disease in a captive flock of brown pelicans. This information may aid in the diagnosis and treatment of brown pelicans with ocular disease.

OCULAR FINDINGS AND SELECT OPHTHALMIC DIAGNOSTIC TESTS IN CAPTIVE AMERICAN WHITE PELICANS (PELECANUS ERYTHRORHYNCHOS)

“…Examination findings from a group of 63 brown pelicans have also been documented pre-viously. 27 In this group of brown pelicans, 46% had a normal ocular examination, similar to the findings in our study (52% were normal). In addition, the most common ophthalmic finding in the brown pelicans was cataract, which was also the case in the American white pelicans presented here.…”

“…Moreover, similar to the birds in our study, several of the brown pelicans also had vitreal degeneration, corneal disease, and globe damage due to suspected trauma. Lack of filoplumes was noted in brown pelicans 27 and the American white pelicans in this study and seems to be a common feature in birds with long bills, possibly allowing unobstructed views of the rostral bill during feeding.…”

“…The American white pelican ( Pelecanus erythrorhynchos ) is popular in zoologic collections, and many detailed studies have been performed to better understand their physical peculiarities. Published studies evaluating the ocular system of pelicans include a summary of ophthalmic diagnostic and examination findings in brown pelicans ( Pelecanus occidentalis ), 27 the quantification of the refractive state in air and water of brown pelicans, 32 and a clinical description of a penetrating keratoplasty in a juvenile brown pelican whereby a full-thickness donor allograft was placed into a full-thickness defect of a recipient pelican that survived 6 wk postopera-tively. 21 To the authors’ knowledge, no published data exist characterizing ophthalmic examination findings or normal ranges for ophthalmic diagnostic tests in the American white pelican.…”

Sphenisciformes, Gaviiformes, Podicipediformes, Procellariiformes, and Pelecaniformes

“…Cataracts are the most commonly reported age related ocular pathology in penguins, and recent evidence suggests that cataracts and vitreal degeneration may be under-recognized in zoo-captive adult pelicans (Bliss et al, 2015;O'Connell et al, 2017). They include arthritis, arteriosclerosis, and hyperkeratosis of the tibiotarsus and tarsometatarsus in shoebills.…”

Avian ophthalmic peculiarities

“…The iris color may vary according to the species, and there may also be intraspecific alteration, depending on the amount and types of pigments, degree of vascularization, age, sex and diet (WILLIS & WILKIE, 1999;BORTOLOTTI et al, 2003;KERN & COLITZ, 2013;WILLIAMS, 2012;RODARTE-ALMEIDA et al, 2013), exposure to polychlorinated biphenyls (BORTOLOTTI et al, 2003) and reproductive season (O'CONNELL et al, 2017). There is a wide range of colors that can be observed, from brown to yellow to blue (BORTOLOTTI et al, 2003;BALDOTTO, 2012;WILLIAMS, 2012;RODARTE-ALMEIDA et al, 2013;MEEKINS et al, 2015).…”