Thanks guys, I had to work tonight....I got an informal warning for being late when Mav died 10 days ago so there was no way I could stay home this time.
Phil has started tidying his stuff away for me.
We have had to freeze Cassius's body as we have all our buns cremated and cannot get him to the vets until Tuesday however freezing will corrupt some of the PM results so I dont feel it is worth persuing further.
Had his behaviour indicated something more sinister such as an infection then I would have attempted a PM anyway but we just cant come up with anything other than a horrible coincidence.