PLEASE NOTE A NEW 4TH EDITION HAS BEEN PUBLISHED AND IS AVAILABLE IN THE LIBRARY AND IN PRINT

Solar-induced dermatitis and neoplasia occur in dogs and cats as a consequence of chronic exposure to sunlight and ultraviolet (UV) radiation on non-pigmented, lightly pigmented or damaged (depigmented or scarred) skin that is unprotected by hair. The deleterious effects of UV radiation on the skin depend upon the duration and frequency of exposure, the intensity of the solar radiation related to the geographical latitude, and the reactivity of the skin based on genetically determined skin colour, hair coat density and genetic susceptibility. Solar-induced skin lesions in dogs and cats are located on non-pigmented, or lightly pigmented, sparsely haired regions of skin that are frequently exposed to the sun. Lesions are more common in dogs and cats that sunbathe or are housed where there is reflective ground cover (including snow) and little sun protection. This is more common in tropical, subtropical, or desert or mountainous regions where animals spend a substantial amount of outdoors, and is most problematic in hot sunny climates such as Australia, California, Florida, Hawaii and South Africa. Many affected dogs are reported to be sunbathers and spend long periods of time in either dorsal or lateral recumbency in direct sunlight. This chapter looks at Actinic (solar) dermatitis; Actinic keratoses; Squamous cell carcinoma; and Cutaneous haemangioma and haemangiosarcoma.