Invisible Virtual Fence


This document will describe how I trained my dogs to stay in the back yard without purchasing a fence, or a punishment based containment system (like “Invisible Fence”).


My yard appears to be fairly large, but in fact is quite small. This is because most of the area behind my house belongs to the housing commons. That means I can use it (and typically I mow most of it), but I cannot erect any permanent structure on it. The piece of land behind my house that I actually do own is too small to be worth the cost of a physical fence.


Instead I began to look into technological solutions. There are two solutions on the market, both based on detecting when an animal has wandered where it is not supposed to wander. One (using amplitude) uses no wires. A base unit sends out a radio signal. When the dog wanders too far from the base unit the collar unit is activated, and the dog is punished. This system is presumably based on RF amplitude. The exact location where the collar unit is activated could vary according to atmospherics; thus, there is no “line” where the collar activates. Most collars have two activation modes, a warning mode (typically a beep) and a punishment mode (an electric shock, or dispersion of an offending odor sprayed into the air).


The other more popular system is the one that requires burying of a cable, which acts as an antenna. When the animal gets near the antenna the collar is activated (again, typically there are two modes, a warning and a punishment mode). This is more difficult to install, but the location of the collar unit activating is a lot more consistent, accurate to probably within an inch.


Many people report these units work well for them. However, I am somewhat dubious of both. A unit that goes into punishment mode could cause agression (toward whatever the animal was looking at when the collar punished). Also, in the event the animal does escape there is a strong disincentive to cross back into the zoned area because it will result in another shock. Some very expensive units require the burying of two cables, which allow the collar unit to distinguish between coming into the restricted zone from outside of it, and leaving the restricted zone. For the more expensive units an animal could return to the back yard without risk of punishment.


I do not know how often the units misfire (punish inappropriately), nor if the units report when their battery is low. Most owners report that their animals do not set the punishment off after the first few days. It should be noted that no unit is really safe, the animal must be monitored always. It should also be noted that many dogs have gotten extremely clever at removing the collars, and will chew it to bits when they get the chance.


These collars train dogs using punishment feedback (P+). This suggests I could train the same thing using treats. I talked to Pat Rattray, my favorite local trainer, who encouraged me to try this and assured me that she (among others) have been successful doing this sort of thing.


So I went to Home Depot and purchased 100 little flags, similar to the ones the utility companies use, for about 8 dollars. I marked off a line that my dogs were not to cross; the Invisible Fence instructions also require a visible boundry. I also purchased a heavy duty Flexi leash (20 foot). I attached the leash to my dog’s Martindale collar (which never punishes, unlike choke or prong collars). I went to the back yard with my dogs (one at a time) and let them wander. When the walked up to the markers I locked the Flexi with my thumb and said “Barrier”. If they turned around and walked to me I gave them a treat. The first two days I did this for about 20 minutes. For the remainder of the next 2 ˝ weeks I did this for about 5-10 minutes per day.


This seemed to be sufficent to train the dogs to remain in the back yard. This seems to have the same reliablity of the electric fence WITHOUT the shocks or nasty odor.


Gary Hughes-Fenchel

June, 2005