Electronic Pet Fences: What You Need to Know

Sep 8, 2014 | Training

Eileen Anderson: Do not reuse this pic!

Boundary flags for an electronic pet containment fence

Electronic fences, e-fences, radio fences, Invisible Fences™, pet containment fences: they all amount to the same thing. A system where your dog wears a radio controlled electronic collar that shocks him whenever he crosses a certain perimeter, sometimes marked (at least at first) with little flags. If you are considering this kind of fence, there are some things you need to know that the people who market them won’t tell you. The fences and accompanying collars are marketed as safe, painless, and foolproof by the companies that make them and the stores and individuals who sell them. And they seem to offer a simple solution for situations where it’s hard or not allowed to put up a real fence. Unfortunately, invisible fences are not safe, they are not foolproof, and they are certainly not painless. But you don’t have to take my word for it.  There’s plenty of evidence, and it’s not on the side of the salespeople. I’ve got no vested interest. But the fence companies and installers do.

Table of Contents

  1. The Warm, Fuzzy Image
  2. About Electric Shock
  3. Problem #1: Your Dog Is Not Safe
  4. Problem #2: The Shock Can Easily Be Associated with the Wrong Thing
  5. Problem #3: Your Dog Can Still Get Out: Then What Happens?
  6. Problem #4: The Collar Can Malfunction or Be Set Incorrectly
  7. Problem #5: You Could Be Liable
  8. “Freedom” for your Dog?
  9. Resources

The Warm, Fuzzy Image: It Sounds So Safe and Harmless!

Here is the product description for one of the well-known electronic fence setups, quoted here for purposes of critique. “The “Famous Brand” wireless fence pet containment system is a revolutionary concept that provides the safest, simplest form of pet containment ever. Plug in the transmitter somewhere inconspicuous in your home. The transmitter emits a 17.5 kHz radio signal around your home. Your pet wears a lightweight receiver collar that “listens” for the signal. While the collar is receiving the signal your dog is free to run and play in your yard. When he approaches the boundary of the signal area he receives a warning beep. If your dog does not return he receives a static correction which is startling but not harmful. With a little simple training your dog will quickly learn his boundaries. The training of your pet is a key element with the “Famous Brand” wireless fence. Follow the easy instruction and training manual that is included.” I hesitate to reproduce this here because it is quite effective persuasive writing. With words and phrases like, “safest,” “simplest,” “inconspicuous,” “lightweight,””free to run and play,” “static correction,” “not harmful,” “simple training,” and “easy instruction,” it paints a picture of something benign, humane, and easy to use, that works consistently. Here is a rewritten version, omitting the warm and fuzzy language and using complete descriptions of the processes involved. “The “Famous Brand” electronic fence system uses a shock collar connected to a radio transmitter with the goal of keeping your dog inside a chosen area. Electric shock has been used in laboratory experiments for decades for behavioral studies to put animals in a state of stress or fear and is also linked to increased aggression. Plug in the transmitter in your house. The transmitter emits a 17.5 kHz radio signal. Your pet wears a shock collar that will be triggered by a change in the signal. The collar must be fastened tightly on the dog’s neck so that the probes will poke through the dog’s fur and press firmly into his skin. Even when not generating a shock, the collar is likely to be quite uncomfortable. While the collar is receiving the standard signal your dog is safe from shock. When he approaches the boundary of the signal area he receives a warning beep. If your dog does not return, or goes through the boundary, he receives a shock to his neck that can range from a tingle to very painful, depending on the setting you choose. The instructions describe how you will test the shock on your dog when you adjust the settings, but there is no objective way to tell exactly how much it will hurt him, or whether it will effectively stop him at the barrier when he is excited. Also, if he triggers the shock by going through the boundary, he will end up outside the designated area and free to go where he wants. He will probably not cross the boundary again to return to the yard. The instruction manual describes how to train your dog to stay inside the boundaries. However, the “Famous Brand” electronic fence system can not be guaranteed harmless or reliable, nor does it have any way to prevent other animals or people from entering your yard. That sounds like a different product, doesn’t it?

About Electric Shock

Eileen Anderson: Do not reuse this pic!In order to make an informed decision about using an electronic fence, you need to understand a bit about the effects of electric shock on animals. The shock collar and e-fence industries go to great lengths to make the shocks induced by collars seem benign, calling them “stims,” “taps,” “sensations,” or “pressure” but they are inarguably electric shocks. In experimental psychology and animal behavior studies, electric shock is the standard laboratory method to scare or hurt an animal and put it into a state of stress. In Seligman’s classic experiments on learned helplessness, inescapable shock was the mechanism by which both rats and dogs shut down and stopped responding. Shocks are sudden, painful, and usually unlike anything the animal has ever felt before. There are  studies of dogs trained with shock collars, including with trainers experienced with the method, that show longterm negative behavior changes centering on fear and stress. The shocking mechanism of collars for electronic fences is the same as that of other shock collars. The two most recent studies of shock collars showed that shock collars are detrimental to dogs’ welfare. This article summarizes the findings of the recent studies along with some previous ones, and also has links to the studies themselves: The End for Shock Collars? Shock collars used for electronic pet fences can likely cause all of the problems referenced by the studies. In addition, there is often no human supervising the dog. (That’s a major reason for having a fence.) That absence increases the chance of the dog associating the shock with events in the environment and causing the problems delineated above, and means that there is no one to help if the collar malfunctions. There is one study specifically addressing electronic fencing systems:

Can Aggression in Dogs Be Elicited Through the Use of Electronic Pet Containment Systems? –Richard Polsky.

The answer to the question posed in the title is that is sure looks that way. Dr. Polsky is appropriately conservative about making broad generalizations but his data are strongly indicative of problems. He analyzes five cases of dog-to-human aggression specifically associated with being shocked by an electronic fence and charts the situations and specific behavior of the dogs. He cites previous research that has shown that shock-induced aggression is typically intense and vicious, with repeated bites. (It should tell us something that shock is also used in laboratories to induce aggressive behavior in animals.) In addition, aggression induced by shock tends to be without the warning signals that dogs usually give when prompted to aggression by external events, and this was borne out by the dog attacks associated with e-fences. Dr. Polsky’s final statement is as follows:

…manufacturers need to acknowledge the risks involved and make consumers aware that the systems are not foolproof and that some dogs could attack a person as a result of having received electric shock.

Following are some of the problems that can easily befall dogs whom people try to contain with an electronic fence.

Problem #1: Your Dog Is Not Safe

Eileen Anderson: Do not reuse this pic!

Sign advertising the brand of an electronic fence

An electronic fence may keep your dog in but it can’t keep anything else out. Electronic fences leave your dog unprotected from humans, animals, or anything else that comes by your house or into your yard. The electronic fence offers your dog zero protection over being teased, harassed, or stolen by humans, attacked by other animals, or ingesting or interacting with anything inappropriate that someone tosses into your yard. The boundary of your yard may not even be clear to passers-by. Unlike with a physical fence, there is absolutely nothing between your dog and the rest of the world. Even if you have the biggest, most imposing dog in the world, it is still vulnerable to harm in this situation. That’s a dealbreaker right there, before we even get to the harm of the actual shock.

Problem #2: The Shock Can Easily Be Associated with the Wrong Thing

Eileen Anderson: Do not reuse this pic!

Sign advertising the brand of an electronic fence

Dogs (and humans) learn by association. We see this all the time. Dogs pay attention to what things might predict other things. Your getting out the clippers means they’re about to get their toenails clipped. Your picking up the leash means they are probably about to go for a walk. They develop emotional responses accordingly. This means that your dog can very easily come to fear and/or aggress towards people and other dogs due to the fence and collar, because if he sees anything that excites him and causes him to run across the boundary, either to flee or aggress, he will get shocked. If that pattern gets repeated just a few times: see mail carrier, get shocked, the appearance of the mail carrier will be associated with bad things happening. There is also the possibility that if you have more than one dog enclosed in such a way, they may become aggressive to each other as a result of receiving shocks. This could happen because of association, if a dog comes to associate the shock to proximity to its yard mate. Or it also could be simple redirection, where an animal aggresses towards something present and convenient if it can’t reach the thing that is scaring or bothering it. Even if you have set up a visible boundary for your dog and followed the training instructions for the electronic fence, that training can never be guaranteed to “stick” during every possible situation. While your dog is calm and just hanging out, he may well stay within the perimeter to avoid being shocked. But if something catches his interest and gets him excited, he may well forget about the perimeter entirely or not notice the warning sounds. This is a terrible thing to happen to a dog who is already afraid. For instance, he fears the UPS truck. When it comes he tries to run away, crosses the perimeter, and gets shocked. Now the UPS truck is even scarier because it has come to predict sudden sharp pain. Equally tragic is what can happen to a friendly dog. Let’s say you have a retriever mix who loves kids. He gets really excited whenever he sees them. Here come some kids. Maybe they are even carrying a ball. Your dog rushes forward to greet them, hits the perimeter, and gets shocked. That doesn’t have to happen many times before your dog comes to associate kids with being hurt. You may have lost your dog’s friendliness forever, and he may become aggressive. You will have no power over what your dog associates with the shock. Electronic fence collars are automated electronic devices and do not care why the dog is approaching the boundary. The dog will get shocked no matter what. Bad experiences like this increase the likelihood of the dog developing fears and even aggression.

Problem #3: Your Dog Can Still Get Out: Then What Happens?

Eileen Anderson: Do not reuse this pic!

Boundary flags for an electronic pet fence

What is the situation after the dog runs through the perimeter and gets shocked? He’s outside the fence, in the presence of whatever triggered him to dash through the perimeter, and he has just received a painful and startling shock. Unless you are right there to take action (and if you were always there, you wouldn’t need the fence) one of the following things will likely happen.

  • Your dog will keep running and get lost;
  • Your dog will attack the thing that was associated with the shock (leashed dog, kid with ball); or
  • If your dog hasn’t been poisoned towards kids yet, maybe the friendly kid will try to lead him back to your house. And make him cross the perimeter and get shocked again while he is walking with the kid, who may even be touching his collar. What do you think your dog will do then?

Veterinary behaviorist Dr. Karen Overall reports that there are cases of humans being bitten when they pulled dogs over the boundary of an electronic fence. [Manual of Clinical Behavioral Medicine for Dogs and Cats, 2013, p. 108-109] The thing you would hope for, that the dog would wait calmly just outside the perimeter, waiting for you to get home and turn the fence off or remove his collar, is not likely to happen. You got the fence because you didn’t figure the dog would stay in the yard in the first place. Once the dog is outside the perimeter, you are pretty much in trouble.

Problem #4: The Collar Can Malfunction or Be Set Incorrectly

Don’t forget that, as with any electronic device, the collars can fail. I know of at least once case of a dog who was under continuous shock because of a short in the collar. You can see a shock collar injury from an e-fence collar in one of the links below. The DEFRA study that is referenced in The End for Shock Collars? found several of the collars purchased for the study were faulty, including one that repeatedly got stuck with the shock on. There’s a more subtle problem as well. The methods that the instructions describe to decide the setting for the individual dog depend entirely on the dog’s response to the shock. In general, you are instructed to experiment on your dog, starting with a very low setting and raising it until you see a reaction. Unfortunately, a response from the dog is not an accurate way to calibrate how much pain they are experiencing. We all know dogs who are very stoic about pain (as well as some who appear to be very sensitive). And the dials of many shock collars do not have equal gradations, so, for instance, the difference between 3 and 4 can be the difference between annoying and terrifying. So it is guesswork. Guesswork with your dog’s life and wellbeing at stake. In addition, the pain experienced by any dog can vary with changes in the environment. The humidity and even your dog getting a haircut can change how well the prongs in the collar conduct electricity into his body (this was also confirmed in the DEFRA study).

Problem #5: You Could Be Liable

By co-author Karen Peak, West Wind Dog Training If the first four reasons didn’t convince you, consider this. If someone comes legitimately onto your property and your dog harms them, you could be held liable. As discussed in Problem #1, e-fences provide no safety to your dog. They also provide no safety to others from your dog. Your dog already may have an increased propensity for aggression due to previous shocks. As described in Problem #2, he can come to associate the warning signal with scary things in the environment, again because of previous shocks. So what happens when the utility man comes onto your property? In most communities there are provisions for delivery people, mail carriers, utility workers, and meter readers to legally enter your property. They are not trespassing. They probably can’t even see a boundary. So when someone comes on your property and startles your dog (already easily stressed and startled because of his history of being beeped at and shocked by the fence), what if he bites them? He can get right to them without danger of shock because there they are, right inside the boundary with him. Veterinary behaviorist Dr. Karen Overall reports that there are “numerous reports of human injury under exactly these circumstances.” [Manual of Clinical Behavioral Medicine for Dogs and Cats, 2013, p. 108-109] I am not a lawyer and don’t play one on TV, but it doesn’t take much legal knowledge to realize that in many communities you will be held liable. Your community will probably consider your dog, who is not subject to a physical restraint system like a fence or a tether, out of control. The utility man had a right to be on your property and expect safety. If you had had a physical fence, he would have had to ask you for entry, but why should he if he doesn’t even see a boundary? (And just try putting up a “Beware of Dog” sign if you have no fence.) So now you are facing fines, and your dog has a bite history and has been designated dangerous. How is your insurance company going to feel about continuing to cover you? And what are you going to do about your dog now? No rescue will take him, and it probably isn’t ethical to rehome him. No electronic fence company, or individual who sells them, has any control over what comes into your dog’s environment. But you are responsible for what happens there.

“Freedom” for your Dog?

The marketing materials of the electronic fence companies often feature photos and videos of dogs romping on huge, lush green lawns without a care in the world. They promise “freedom” for your dog, over and over again.  We (USA folks in particular) are practically wired to have a positive response to that word. But frankly, is a dog alone in a yard, with an automated electronic shock collar strapped tightly around its neck, really free?

It’s a myth that [electronic fences] provide dogs with more freedom. In fact, these devices violate three of five freedoms that define adequate welfare for animals: • Freedom from pain, injury, and disease • Freedom to express normal behavior • Freedom from fear and distress–Karen Overall, Manual of Clinical Behavioral Medicine for Dogs and Cats, 2013

I know that many, many people who install electronic containment fences have their dogs’ best interests in mind. The salespeople have told them the collars don’t really hurt the dog. They may figure in any case that a little “tap” once in a while is worth it for their dog’s safety. I hope I’ve shown you here that the pain is probably not trivial, and the safety is definitely illusory.

All photographs courtesy of and copyright John Stawicki. Thanks John!


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