Page 1011 - The Veterinary Care of the Horse

scarring. However, the treatment may affect the pigment producing cells so the new skin

and hair are white. This treatment is costly and is only available at specialist centres.
VetBooks.ir • Do nothing, e.g. in cases where the tumour is widespread and malignant. Irradiation may

be the only realistic treatment and as discussed above this is expensive and not widely
available. Inappropriate interference may make the situation worse.

Squamous cell carcinomas

Squamous cell carcinomas may develop in several sites on and around the eye including the
eyelids, conjunctiva, third eyelid, sclera and cornea. (Figure 21.26.) High levels of ultraviolet

radiation from sunlight and non-pigmented skin predispose to this type of tumour which
often resembles granulation tissue (proud flesh) in appearance. The tumour tissue is raised

and slightly knobbly looking, pink in colour and may bleed easily. There may be a
mucopurulent discharge from the affected eye.

Figure 21.26 Squamous cell carcinoma

The risk of developing squamous cell carcinomas can be reduced by keeping susceptible
horses out of the sun or turning them out with protective masks Figure 21.27).