obsessed with shadows on ceiling

[maureen dalton]

I have a 11 month old Border Collie called Meg, she spends all her time every day stressing over our ceiling! she runs round in circles staring up at the ceiling, if she sees a reflection or a shadow there she goes beserk trying to get up to it, she gets on her hind legs barking and whining and generally getting very distressed. I have tried turning all the lights out so there is nothing there but she still runs round in circles looking up anyway. When people come to the house she is very friendly but only stays a few seconds to say hello and then she runs straight back to watch the ceiling again.
Does anyone have any ideas of how to deal with this obsessive behaviour?

[stlucia91]

We too have a shadow chaser,it can even be so small that we cant see it,but she can.
From the beam of light from the fridge door opening,the back door opening and a reflection of light moves across the garden,mobiles throwing a shadow of light when the turn around,
its not a problem until she starts to bark insestantly,she has also broke her teeth grabbing a shadow on the wall (or trying to)
she is a blue merle border collie and this is quite common with merles .no cure as of yet,we usually close the curtains that can help if its very sunny outside.
:d