Which condition can cause photophobia in canines?

Photophobia, or light sensitivity, in canines can be caused by conditions affecting the eyes and surrounding structures, with pain in the ciliary body being one of the primary reasons. The ciliary body is part of the eye that controls the shape of the lens and is involved in the production of aqueous humor. When inflammation or pain occurs in this area, it can lead to discomfort in response to light, resulting in photophobia. Conditions such as uveitis or other inflammatory diseases of the eye can affect the ciliary body, subsequently causing light sensitivity in the affected dog.

In contrast, while injury to the cornea can also lead to light sensitivity—since damaged corneal tissues can be painful—pain primarily originating from the ciliary body directly correlates with photophobia due to its role in the eye's overall function and sensitivity. Dislocation of the jaw is not associated with light sensitivity, as it pertains more to the mechanics of eating and jaw mobility rather than visual discomfort. Chronic ear infections, while painful and potentially leading to discomfort, do not typically result in photophobia since they are not directly linked to the eye's structures. Thus, pain in the ciliary body stands out as the most direct cause of photophobia in canines among the