Invisible Fences: The Good, The Bad, and The Ugly

Dog in front yard behind an invisible fence

Many homeowners rely on underground, or invisible fences to contain their furry family on their property. Sometimes this choice is made because the property is quite large, and a physical fence would be cost prohibitive. Other times, it’s the community rules that prohibit physical fencing for aesthetic reasons.


The Good

The only “good” part of using invisible fencing is the aesthetic. It allows for a large, open view, free of the choppiness of property fencing.


The Bad

When trained well, dogs wearing their fencing collars will remain on their property and avoid going near the designated property lines. Unfortunately, such “fencing” does not prevent other animals from coming onto the property, setting the resident animals up to be harassed or attacked, and possibly even dragged off property. It also doesn’t prevent humans from easily walking onto the property and stealing or injuring your beloved family member.


Even well-trained dogs may not be completely contained. If a dog is sufficiently motivated to get off the property – say to chase a squirrel or other critter – that motivation to leave the property may outweigh the fear of getting shocked by the boundary wire (Masson, et al., 2018; Polsky, 2000). This means that your containment system did not successfully contain your pet. And even worse, most pets, once off the property, are more scared of the shock than they are motivated to go home, and so become trapped off property, unwilling to cross the boundary wire to get back home. This leaves these dogs susceptible to unsafe interactions with other free-roaming or wild animals. It also increases their risk of being hit by a car.


I’ve also had several clients forget to remove the fence collar before taking their dog off property, forcing the dog to be shocked as they cross the boundary line. This can cause an association with going for walks or car rides, or interactions with the owner with the experience of pain and fear of being shocked.


The Ugly

These are the most important reasons why I do not condone the use of underground fencing systems. There is a significant increase in what we call “behavior fallout”. Behavior fallout refers to unintended behavior changes, usually increased fear behaviors or increased aggression displays.


With regard to underground fencing systems, there are numerous published studies showing links between the use of shock and a change in behavior from non-aggressive to aggressive (Polsky, 2000). Specifically, in each case, the dog was wearing a properly functioning collar inside the containment area and either in or near the signal field (where the collar will be triggered to give the dog a shock). The greatest risk to this increase in aggressive behavior was that the shock was completely out of context with the behavior the dog was engaged in – usually greeting someone (Overall, 2007; Polsky, 2000). For the pet parent, the important take-away here is that if the dog is wearing a fencing collar and approaches the property line to greet someone, maybe even a child, and the dog gets shocked in the process, the dog is likely to become defensive in that moment and may attack that person. Further, the dog may associate the approach of people with the shock, and may generalize this to many situations, making the dog defensive with all new people.


And the more sociable the dog is, the more likely this aggressive/reactive outcome is to occur. Why? Because highly sociable dogs are more likely to respond to the presence of a person near their yard by approaching to greet, maybe in the hopes of pets or a quick game of fetch. But they will get a shock for their efforts, and the association made will be that visitors are dangerous. Because we can’t control the type of visitors which happen by, we could be setting our dogs up to become defensive with adults, children, other sociable dogs, cats, delivery people, first responders, etc.


I have had client dogs have even broader fear-related responses due to the use of invisible fencing. In one case, after just the first time experiencing the shock near the boundary, the dog became so fearful of the entire yard, that the dog refused to go through the back door again and would not step foot in their large, and very dog-friendly back yard. Another client had an even greater fear response. In this case, the dog associated the grass with the scary shock. That dog refused to step on any grass, anywhere, and would only potty on concrete or dirt while avoiding touching any grass at all. It did not resolve until more than 6 months after the dog was moved to a new home, with another dog who was comfortable on grass. Finally, after 6 months of watching her dog friend run on the grass, this dog took her first tentative steps onto grass again. It took another 2 months before she was stepping on grass without hesitation!


In short, between the risk of unintended associations that can create increased risk of aggression, and the risk of extreme fear responses, I find that these units are inhumane and fail to consider the emotional welfare of our best friends. If your property is too large to be fully fenced, then fencing a smaller portion may be an option, even if it’s just a 10X10 enclosure for unsupervised yard time. A physical barrier keeps your pets safe from intruders and minimizes the risk of the dog being hit by a car. If fencing of any kind is simply not an option, then supervising outside time with the dog on a long line (50-foot line), or an overhead zip-line – attached to a harness with a back leash snap, not to a collar on their neck – is an excellent and more humane alternative than using shock to try to contain your dogs. You’ll still need to supervise to ensure strangers or random animals cannot harass or attack your dog. But, supervising provides an excellent opportunity to build your bond with your dog through play and just spending time together. A physical barrier is the safest option, and always my preference and recommendation.


If you have any further questions regarding the hazards of using underground (invisible) fence systems, please feel free to reach out to us for more information.


Masson, S., et al., 2018. Electronic training devices: Discussion on the pros and cons of their use in dogs as a basis for the position statement of the European Society of Veterinary Clinical Ethology. Journal of Veterinary Behavior, 25(71-75)


Overall, K., 2007. Why electric shock is not behavior modification. Journal of Veterinary Behavior: Clinical Applications and Research, 2(1-4).


Polsky, R., 2000. Can aggression in dogs be elicited through the use of electric pet containment systems? Journal of Applied animal Welfare Science, 3:4(345-357).

Jody Epstein Author Bio Pic

Author - Jody Epstein

Jody Epstein is a certified behavior consultant, certified professional dog trainer, and holds a master’s degree in animal behavior from Tufts University. She has been training professionally for more than 12 years and is pleased to be part of the Academy of Pet Careers team, teaching the next generation of trainers. Look out for her blogs on all things dog training and animal behavior.