The most common cancer of the bovine eye is squamous cell carcinoma. Economic losses attributed to the disease result from condemnation at slaughter and a reduction of productive lifespan. It is most common in the Hereford type and typically appears in cattle around 8 years old. There are several predisposing factors such as sunlight exposure, light pigmentation around the eye, heritability, nutrition, and possibly even a link to viral insults. Lesions may appear at the margins, on the eyelids, conjunctiva, or third eyelid known as the third eyelid. Cattle with darkly pigmented face and around the eyes tend to have less incidences of the disease.
Usually, only one eye is affected, but it is possible to see involvement on both sides. Lesions begin with a smooth mass that progresses to a papilloma or skips straight to a malignant squamous cell tumor in some cases. Treatment is focused on mass removal and if caught early and on the 3rd eyelid, removal is usually curative. In advanced cases removal of the eye may be necessary. Re-occurrence varies depending on the onset, location, and margins during surgical removal.