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

Objective To establish reference values and report ophthalmic examination findings in a colony of captive brown pelicans (Pelecanus occidentalis). Design Descriptive study. Animals studied Sixty-three captive brown pelicans in Florida were examined. Procedures A complete ophthalmic examination including Schirmer tear test (STT), applanation tonometry, fluorescein stain, biomicroscopy, and direct and indirect ophthalmoscopy was performed. A-scan ultrasonography was performed to measure axial globe length (AGL), anterior chamber depth (ACD), lens thickness, and vitreal chamber length. Fifty-two adults and 11 juvenile pelicans with an age range of 4 months to 38 years were evaluated. Results Twenty-nine pelicans (46%) had a normal ocular examination. Mean STT in normal pelicans was 5.45 ± 1.88 mm/min. Mean intraocular pressure (IOP) in normal pelicans was 10.86 ± 1.61 mmHg. One pelican was fluorescein positive unilaterally. Mean AGL was 20.70 ± 0.62 mm. Mean ACD was 3.38 ± 0.19 mm. Mean axial lens diameter (ALD) was 5.19 ± 0.23 mm. Mean vitreal chamber depth (VCD) was 12.15 ± 0.53 mm. Twenty-three pelicans (36.51%) had cataracts, 17 pelicans (26.98%) had vitreal degeneration, 18 pelicans (28.57%) had corneal disease, and seven pelicans (11.11%) had evidence of significant ocular trauma, which included collapsed anterior chamber or lens luxation. Conclusions and clinical relevance 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.