We have a "run", which is basically a cable that stretches from one corner of our deck to a tree.
If a fence is really impossible, trainers do consider this a reasonable option for the times when you want to have a dog outside (of course, when someone is still around) and is safe and humane.
Because the line is overhead, it gives dogs a lot of room in which to safely run back and forth without the risk of getting entangled. Note that it is quite different from staking a dog out on a chain or rope, which is sometimes okay if someone is sitting right there and watching a dog, but risky otherwise (in some areas, it's actually illegal to stake out dogs in this way).
One reason a cavalier will sit and “mope” by a pen is that many dogs, and most cavaliers, just find being left in a pen or outside alone, way too boring. They need active play with people, whether on walks or in a safe area in a park, etc.
Cavaliers will not run around and exercise themselves if put out into a garden. Most will sit and begin to whine or bark to be let back in and can become really anxious and even destructive –behavior that often will be duplicated if they are put outside in a pan. It is nice if they can have an area that they can wander out to, safely, out of the door–like Nicki suggests, possibly setting up a play area that is safely attached to a door area–mine like to do this when the sun is coming in to the front hallway. If I am working just outside or in the hall, I will take my puppy pen pieces and hook them into the doorframe and around a radiator and then run them outside so that they have a little porch area where they can watch people go by and lie in the sun.
But really–I think people probably are mistaken in thinking there is any need to have a large garden for entertaining a dog, especially a cavalier–and it is definitely a mistake to think the dog will go out and get lots of exercise running around alone, as they generally don't. Dogs would much rather get their exercise out on a walk with their people, or playing somewhere and some of the saddest, most neglected dogs I have come across in working with my trainer friends and in doing rescue, are dogs that live in homes with big gardens, as people so often just leave the dog alone in the extremely un-stimulating surroundings of a garden and think that that is giving the dog exercise and entertainment.
Some of the very best homes I've ever put dogs into have been people that own condominiums or apartments, or small houses with little/no gardens, because that means the dog is going to get out on numerous walks every single day for toileting and exercise. I know this myself :lol: –I have only a small side garden in my city house, but my dogs get at least an hour total of walks daily, spread out over 4 different sessions, 1st thing in the morning, last thing at night, and more during the day. Often one of those walks is an hour or two spent running in the massive nearby park, at a beach or on trails in the nearby Dublin or Wicklow mountains, where they can be off lead (a dog that would like to run around more but isn't reliable off lead can be taken out on a 25 m long lead used for recall training, easily available in many pet shops or online as a training aid. Handheld extensa leads can be far more risky because they easily pop out of the hand, and many dogs will bolt in terror because they are dragging the handpiece behind them. You can get a wrist strap to make extensa leads safer and for a dog that is comfortable and won't bolt, they can be a great solution in areas well away from traffic).
I often think about something Thelly, who home boards dogs, once told me–she only takes in small breeds, and she says all the other dogs will go out in the fenced garden area except the cavaliers–who like to sit inside on the armchairs and sofas!:lol: The cavaliers usually only go out if a person goes out with them
. I have found that this is true in my partner's house too, which is on many acres. If we are in the house, the cavaliers all stay inside. Once we go out, then they are ready for action (especially, of course, Jaspar...). But they really could care less that they have acres of land over there versus no acres over here
. Good times as far as they are concerned, and the opportunity for exercise and action, are entirely connected to what we actively do with them either on or off lead.