Anisocoria in cats

©Barnett, KC & Crispin, SM Feline Ophthalmology (2002) Saunders

Anisocoria (inequality of pupil size) may arise as a result of abnormalities of the eye, the oculosympathetic system, the light reflex pathway, the midbrain or the cerebellum. The underlying cause is not always obvious, particularly in relation to inflammatory disorders and detailed investigations may be required. It is important to detect which eye is abnormal when anisocoria is present, and this may require careful observation of direct and consensual pupillary light reflexes and pupillary dilation in response to low light conditions. Other causes of anisocoria such as congenital  or acquired iris problems (e.g. iris hypoplasia, iris atrophy and iritis), glaucoma and fundus abnormalities should be considered.

Anisocoria in FIP infection	Anisocoria in FeLV infection