Any disorder of the brain or spinal cord, of muscle, bone or joints, resulting in incoordination and a tendency for sheep to fall or become recumbent, is referred to as 'staggers'. This can manifest in a few individual animals or may be seen affecting a large proportion of a mob simultaneously or within a short time. Animals manifesting such signs may recover temporarily or permanently, or deaths may occur.
Courtesy of Sheep Vet Online.
My flock of daleks have come down with something of the same. I am not sure what to do.