Pannus (Chronic Superficial Keratitis)

Pannus is a condition in which the immune system begins to treat part of the eye's surface as something foreign, leading to inflammation and the gradual appearance of a pigmented, fleshy tissue that can grow across the cornea. It tends to start at the outer edge of the eye and move inward over time, and both eyes are often affected, though not always at the same rate. Certain breeds, particularly German Shepherd Dogs and their relatives, develop this condition more often than others, and it is sometimes referred to as chronic superficial keratitis. Owners often notice a dark or reddish discolouration beginning at the corner of the eye, or a hazy, thickened appearance to the clear part of the eye. In some animals, there may be slight discharge or mild squinting, though many dogs show little obvious discomfort in the early stages. The changes can be subtle at first and may be mistaken for a simple irritation or ageing. This page explores what an owner may observe, what is happening beneath the surface, how the condition is investigated, and the range of approaches used to manage it over time.