Squamous cell carcinomas (SCC) are caused by high levels of exposure to the B fraction of ultraviolet radiation (UVB), on susceptible animal tissue. The UVB energy enters the basal cell of the dermis and mutates the DNA; this mutation results in the uncontrolled proliferation of the squamous cells. Factors that influence the ultraviolet radiation (UVR) levels across the globe include altitude, intensity and duration of sunlight, and the thickness of the ozone layer. In this presentation comparative values of the ultraviolet index (UVI) of the Southern and Northern Hemispheres over the last ten years will be reported and discussed.

This presentation describes sixteen years of clinical experience of dogs and cats in South Africa afflicted with SCC.

Typical clinical lesions of the dog and cat will be shown. Treatment with megavoltage electron radiation therapy with/without surgery will be described and discussed. Finally the prevention and prognosis of SCC will be considered in the present-day difficulties caused by climate change.