I have strong feelings about invisible fencing, and, in fact, I will not place any of my puppies in homes that use it. Here are my reasons. (1) Belgians as a herding breed have a very strong instinctive desire to chase after moving animals, cars, or bicycles (and try to round them up), especially if they come from working performance lines. Belgians are also territorial and likely to want to chase intruder dogs away. A smart Belgian with herding instinct or prey drive might deliberately take on the electric shock if a deer or an intruder dog went by. But, once your dog was out it would not be able to get back in, being reluctant to take on the pain of the collar shock without the adrenaline surge that helped it go through in the first place. (2) Invisible fencing does not keep dangerous animals OUT of your yard -- a loose dog that is aggressive, a raccoon or fox with rabies or distemper, could be a big threat to your dog. It also does not keep people out -- a unruly child or teenager with a stick. Besides the safety of the dog itself, in this day and age we also have to keep lawsuits in mind. Even if a friendly neighbor child walked into your yard and your puppy greeted the child exuberantly and knocked it down and the child broke its arm you could get sued. To quote Robert Frost, "Good fences make good neighbors." (3) The collars will wear down the beautiful neck fur. If an e-collar is left on too long, or the dog gets its neck wet while wearing the collar, the prongs can make an ugly, infected hole. (4) Belgians are a "reactive" breed, and are totally unsuited to electronic training methods. Shock aversives can have weird effects on them, especially as puppies and teenagers. These devices make many Belgians nervous and paranoid, and many will injure themselves deliberately to escape. Shock aversives can also "mark" fears causing the dog to associate the shock with something the dog may happen to see at that moment. (5) Many dog owners have had tragic experiences with invisible fencing, which they thought was so wonderful to begin with, right up until the day the tragedy happened. I know so many stories! Here are two. A lovely Tervuren bitch sired by one of my dogs went through the invisible fencing in panic mode, and got chewed up by some loose dogs. It was horrible and totally unexpected. One of the most compelling reasons against an invisible fencing system is the following story. A couple that came to look at a friend's Terv litter formerly owned an Akita who, like many Belgians, had prey drive. They lived in an upscale suburban area where fences were discouraged and so they put in an invisible fence and it did contain the dog. They had a neighbor with a child who liked to ride his bike up and down the driveway next door -- and the dog would chase him...and get shocked. No one ever gave it a thought until the day their grandson invited the kid next door over to the house. The Akita, associating the child with pain, attacked. The end result was a child with over 40 stitches and a dead dog. The problems and heartache that other people have experienced are not what I want to chance for one of my puppies. As far as fencing in general is concerned, most Tervuren breeders will not place a puppy in a home without fencing because of the above already mentioned facts -- that Belgians are a herding breed with a very strong instinctive desire to go after moving animals (and round them up). And, that Belgians are also territorial and likely to want to chase intruder dogs away. Even a well trained adult Tervuren might yield to instinct to chase a deer, squirrel, cat or other dog across the street and get hit by a car. Youngsters and teenagers? Forget about it! Can you go hiking or running with your Terv off leash in the woods or far away from a road? Sure, provided you have a good recall and the dog cannot get into trouble if instinct takes over. Can you have your Terv off leash near a road with cars going by? No, not safely. And you certainly won't be able to leave your Tervuren outside unsupervised and have it be safe unless it is in a securely fenced area. Some dog breeds seem to do okay without fencing and to understand roads and cars. This is definitely not one of those breeds! I know of extremely well trained adult Belgians that have been hit by cars. And then there are rural areas where loose dogs are shot if they wander near livestock, or just because they look like coyotes or foxes. So, what can people with large properties do to get around the fencing problem? A good solution is to fence off a portion of the property to make an outdoor play area near the house. This has worked well for many people. If a real fence is just not possible for you, please consider a different breed.