He has been a bit mopey this evening and looking like he's feeling sorry for himself but he hasn't tried to lick once since we got home so I'm pleased about that.

Thank you for your advice Mini, I'm so glad I took him to the vets today rather than leaving it a day or two. Hopefully now with the gel I can get him on the road to recovery and back to his normal self. I feel bad for him as he always seems to have something going on.