Presumptive keratoglobus in a great horned owl (Bubo virginianus)

Abstract

A juvenile to young adult, male, great horned owl (Bubo virginianus,GHOW) was presented to the wildlife rehabilitation hospital at Lindsay Wildlife Museum (WRHLWM) due to trauma to the right patagium from barbed wire entanglement. On presentation, both corneas were irregular, dry, and no movement of the third eyelid was noted. A severe corneal enlargement/globoid appearance was the predominant ophthalmic feature. The fundus was normal in both eyes (OU). Over the course of several days, both corneas developed edema combined with further dessication at the ocular surface associated with diffuse dorsal fluorescein stain uptake. Repeated ophthalmic examinations found normal intraocular pressures and an inability to move the third eyelid over the enlarged corneas. The bird was deemed nonreleasable due to severe wing damage and poor prognosis associated with eye abnormalities and was humanely euthanized. Postmortem CT, enucleation, and histopathology were performed to evaluate the ocular anatomical abnormality and confirm the suspected diagnosis of keratoglobus. This GHOW represents the first reported case of presumptive keratoglobus in a raptor.

Comparison of anterior segment health in wild and captive common murres

“…This is in contrast to captive murres that are more likely to be affected by age‐related diseases of the eye affecting the lens. These findings are not unexpected as one would postulate that an animal in the wild is much more likely to suffer ocular trauma, similar to what is seen in raptors, compared to an animal in captivity who does not have to hunt and spends more time out of the water. Additionally, animals typically live longer in captivity and are therefore more prone to age‐related diseases such as lenticular sclerosis and some forms of cataracts.…”

Lipoidal corneal degeneration in aged falcons

“…Bilateral idiopathic corneal opacification associated with microcornea has been reported in a Barred owl ( Strix varia ) . Presumptive keratoglobus has been described in a great‐horned owl ( Bubo virginianus ) . A progressive unilateral crystalline degeneration of the cornea has been reported in a common buzzard .…”

“…There are few reported cases of nontraumatic, idiopathic corneal disease in raptors . Bilateral idiopathic corneal opacification associated with microcornea has been reported in a Barred owl ( Strix varia ) .…”