Elisa M. González-Alonso-Alegre1, DVM, PhD; Eva Martínez-Nevado2, DVM; Alfonso Rodríguez-Alvaro1, DVM, PhD
Keratopathies have been reported in dolphins living under human care in different geographical areas, but not in Europe.1 Keratopathies are classified as medial, horizontal and temporal. Ultraviolet radiation seems to be the main trigger in medial and temporal keratopathy. Horizontal keratopathy seems to be related to a water quality imbalance.1,2 Slit-lamp evaluation and digital photography of each eye was performed in 21 bottlenose dolphins (Tursiops truncatus) of two facilities in Spain (Zoo-Aquarium Madrid and Aquopolis Costa Daurada).
The mean age of animals was 18.5 years (range 3–49 years). Thirteen (61.9%) were female and 8 (38.1%) male. Seventeen animals (81%), 31 eyes (74%), presented keratopathy. In 3 animals (17.6%) lesions were unilateral and in 17 (82.4%) bilateral. Twelve of the affected animals (70.6%), 23 eyes (74.2%), had horizontal keratopathy. Four animals (23.5%), 7 eyes (22.6%), presented temporal keratopathy and 1 animal (5.9%), 1 eye (3.2%), medial keratopathy. Six of the eyes (26.1%) with horizontal keratopathy, also presented temporal keratopathy.
Medial keratopathy has been previously described as the more frequent keratopathy (53.9% of examined animals).1 This difference could be due to the difference in latitude of the geographical areas included in both studies. In the same study, horizontal keratopathy (22.8% of animals) was less common, probably due to a better control of water quality in the facilities included in the study.1
Incidence of keratopathy is high in dolphins under human care. Periodic ophthalmic examinations and deep analysis of environmental factors are essential to clarify and prevent this condition.
1. Colitz CMH, Walsh MT, McCulloch SD. Characterization of anterior segment ophthalmologic lesions identified in free-ranging dolphins and those under human care. J Zoo Wildl Med. 2016;47:56–75.
2. Kern TJ, Colitz CMH. Exotic animal ophthalmology. In: Gelatt KN, Gilger BC, Kern TJ, eds. Veterinary Ophthalmology. Fifth edition. Wiley-Blackwell; 2013:1793–1800.