I have been back to the vet today as I was called away from work saying the chin is covered in drool. It is the second worst case I have seen and I was the proud owner of a 23 year old chin that encompassed problems in her final year
Anyway vet see me as an emergency. Further inspection, he cannot see anything "clinically, medically, or scientifically that's wrong". He's administered an anti inflam, and baytril. However has asked me to see a specialist tomorrow morning, which I am booked in to do so.
Many thanks for your response GrayRodent. I will happily keep you all posted
Alan