This is Mac. Mac is a 7 year old Greyhound with lots of neck pain and if you look very closely

the muscles over his shoulder have disappeared and only bone is left. This is Mac just before surgery.

A myelogram is where radio-opaque dye is placed in into the area around the spinal cord

A close up when looking from the side shows an area that doesnt have dye in it because the cord is being compressed.

Just above the 'x' you can see the dye is moving upward, indicating that it is a mass outside the cord, not within it.

Again in close up you can see the dye moving across to the right (which is left on Mac) and it is thinning

which means the cord is being pressed.

Sara and Geoff in surgery

In the middle of the picture running left to right is a smooth white tissue - that is the spinal cord.

Just under it is a red/brown tissue that is a tumour - probably a nerve root tumour that was responsible for

compressing the spinal cord and damaging the nerve innervating the muscles of the shoulder.