When we stayed there they did not allow dogs so some people were sleeping their dogs in their cars. I think it is very short sighted of the hotel not to allow dogs as it is such an amazing place to walk it is bound to attract dog owners.
Ring the hotel to ask the question.
As for the hotel being short sighted not to take dogs - not all of us like dogs. In fact my husband is allergic to animals especially dogs and cats. If he stayed somewhere where an animal had been he would be covered in a rash, his eyes red and swollen, coughing and have difficulty breathing! If you want a dog friendly hotel go somewhere else.
Get an answer from The St Enodoc Hotel staff and past guests.