Many people put some reflectors on their dogs, but this size?
BTW, this photograph was made around 2 pm.
Reflector for Dogs
Before (left) and After (right)
Camera: Canon 7D ISO 125 and 1/160
Lens: Canon 70-200 f/4L IS @127mm and f/4.5
Processed with Darktable 2.0.4: http://www.darktable.org/