I have a friend who has a 6-7 month old working Golden Retriever pup. He’s still quite a small dog as he is young. She has been informed that she has had a complaint from a neighbour to the police and local dog warden that it the crate she has been using for transportation is too small for him. 

I’ve seen the crate myself and it looks fine, he can lay down and sit in it (albe it his head is lowered a little) with no discomfort and has space to move to different comfortable positions and generally sleeps in it while travelling. 

However they have not told her what the legal acceptable size is.

My questions are: 

1) Is there a legal ground for this in the UK?
2) If so what is the legal size dog crate she should be looking for?