Well, we've had the blood tests back and there is nothing conclusive!
His thyroid, white blood count, kidney functions, etc are all normal. The only thing was slightly raised potassium but that could be because of the age of the sample.
The vet is going to refer us to either the Animal Health Trust in newmarket or Cambridge Uni for neurological testing.
I want to go straight away to an acupuncturist or chiropractor but OH thinks we should wait a bit.
Will keep you updated. Am really upset because I was hoping to have some answers today!