Leaving dogs unattended in van

I was always under the impression that it was not allowed to leave dogs unaccompanied in your caravan whilst staying on Club sites.

We are currently on the NYM site, near Whitby and there is a poor dog barking and whining in the van next to us.  The owners went out this morning and given the experience of the last few days, are unlikely to be back until 1800 or so. It is clearly in distress - although how much is anyone's guess.

We have approached the wardens who are aware of the barking (the pitch is not far from the office) and told Ros, that the dog has been barking since the owners went out.  They had been told that it was being left on its own but had water and a bed and, in fairness, they have left all the roof lights open. It is nevertheless upsetting to have to listen to it. Mrs Warden also said that she was not aware of any rule preventing dogs being left on their own.

Having had a look at the CAMC leaflet - "Touring with Dogs" - it appears that she is correct:-

"Dogs can become anxious when lonely or uncomfortable. To minimise this, make sure
they have somewhere cool to relax, with good ventilation and access to an ample supply of drinking water if you do have to leave them for short times.
Where possible, please keep your dog with you, especially on hot days. A quick build-up of temperatures in cars, awnings, outfits or tents can be fatal to animals."

This isn't a complaint about barking dogs - my complaint, if I have one - is about inconsiderate owners who, in my opinion, are not fit to look after an animal.

Have the rules changed - and if so - why, because it doesn't seem fair to the dog!