Eye cancer is the most common form of cancer in cattle. It is a tumour of the eyelid or eyeball most commonly seen in Hereford or Poll Hereford cattle or white-faced Friesians.
Eye cancers may cause losses to producers due to condemnation at the abattoir and loss of potential production of affected stock, and also suffering in cattle if left unchecked.
Eye cancers occur as a result of life long exposure to sunlight.
The tumour begins as a tiny growth and steadily increases in size. It may invade surrounding tissues and spread to other parts of the body.
The severity of eye cancers can be reduced by the early identification of growths and prompt action to treat or cull.
The incidence can be reduced by genetic selection by selecting animals with pigmentation in the sclera ‘white’ of the eye and the eyelid.
The course of action that should be followed depends largely upon the size and severity of the cancer. Small eye cancers may be readily cured by prompt veterinary treatment.
However if the owner elects to cull the following guidelines should be used:
· If the cancer is smaller than a five-cent piece, clean, and not flyblown the animal can be sold through a saleyard for slaughter only.
· If the cancer is sized between a five and 20-cent piece, clean, and not flyblown the animal can be sold directly to an abattoir only.
· If the cancer is bleeding, purulent (infected), flyblown or larger than a 20 cent piece the animal should be immediately disposed on farm or via a knackery.
Owners who fail to take reasonable action to prevent suffering in their animals may be considered for prosecution under the Prevention of Cruelty to Animals Act.
A photographic guide regarding the course of action that should be followed for different sized eye cancers is available from DEDJTR.
Dr Jeff Cave
District Veterinary Officer