You know how on cloudy days the sun shines bright and gets covered by cloud, and then shines bright again? For some reason, probably the Seratonin in the gut, this affects dogs very much, especially the chorea and digestion-affected dogs and of course the dying (who really suffer when this happens). The variation of the light intensity drives them crazy with itching. When I was weak with Scabies, I felt the sun effect like a dying dog - like the life was leaving me out of my root chakra or tail bone. How much worse it must be for them, poor things!
Assuming it would help to use Seratonin 30, I gave Reiki to it, and the itching for my chorea dog Kenchu decreased and went away. He stopped yowling. Maybe this is the solution to the Sun's incredible effects on the sick and dying. I could never stand the last few days to a dog's death because of the agony they go through in partially-cloudy weather.