Hoping that you've found the emergency vets, is Cadbury dehydrated? (Test by gently pinching the skin, it should spring back into shape, if it stays pinched then it indicates dehydration).
Is there any chance that Cadbury could have eaten a foreign object such as a sock or part of a tennis ball? If so, then you need to see the vet asap.
We're sending lots of hugs from Carlisle and hoping that Cadbury recovers soon.