I posted on here about Murphy giving blood at the end of September. I got a letter in the post today saying that they detected a minor abnormality in Murphy's blood. His level of eosionophils were slightly high, and that this could be a sign of worms/fleas/allergy. We had used advocate on him a few weeks before and he's up to date with his worming, so I'm almost certain that's not it. He has always had bad skin, so perhaps it is some sort of allergy?
They said to ring our local vet in a few days as they are posting the results to them as well