I have a Border Terrier & a shiba that have suddenly started sneezing & snorting. They have not been exposed to Kennel Cough / have not got kennel cough. I have changed the bedding to no avail. They live in an indoor kennel block with plenty of ventilation. I am concerned as the Border Terrier is expecting her first litter of puppies in Mch and therefore cannot have any medication. Neither seem to be suffering, happy as normal, but seems worse when excited both eating fine - any ideas ?

Sounds like kennel cough to me guest! It's an airborne virus so your dogs may have been exposed without you being aware of it.