We had a brucellosis test years ago - they came to test 10% of the flock. We had five sheep at the time
We've had cattle inspections every year since we claimed under the Scottish Beef Scheme, which I suppose is fair enough. The inspections are unannounced. One of my cows always manages to lose a tag just before they arrive but you have 28 days to replace it. TBH I've always found them helpful and reasonable.