A case report of Anisocoria in a Eurasian eagle-owl (Bubo bubo)

This report describes a case of anisocoria in a Eurasian eagle owl (Bubo bubo). A Eurasian eagle owl was presented to the rehabilitation center of general department of environment of Lorestan province. The owl had been found by an environmental ranger; it was unable to fly. On clinical examination the bird was mildly dehydrated, its attitude was dull and had ruffled feather. Clinical examination, whole body radiograph and different laboratory diagnoses were made to identify all abnormalities. Initial treatment included subcutaneous administration of 5 ml lactated Ringer’s solution, and 0·5 mg/kg meloxicam administered orally once daily. On the next day, by covering of either eye separately, the ability of bird to react to different stimuli was measured which revealed that right eye vision is impaired. Ocular examination also revealed a dilated right pupil (anisocoria in the right eye). The left pupil had a normal diameter for the ambient illumination. The ophthalmic examination indicated normal lens, vitreous, retinas and optic nerves. The eyelids, corneas and irises were also normal. Ten days after presentation, all clinical signs had resolved and the owl showed no clinical abnormalities, although anisocoria remained in the right eye. Based on the history, physical examination and radiograph previous trauma was suspected. This is the first report of anisocoria in an immature Eurasian eagle owl.