"Feeder Hand" , a new tool for testing and behavior modification

developed by Pam Green , © 2005

The Feeder Hand is a fake hand which can dispense food. Like the Sue Sternberg "Assess-a-HandTM", the Feeder Hand allows a shelter worker or rescue worker or behaviorist to test a dog for possible aggression in situations involving an approaching human hand in a way that is safe. Because the Feeder Hand can also release a piece of food to the dog, it can also be used to begin the process of desensitization and counter-conditioning to teach the dog to welcome the approach and touch of a hand.

Artificial hand able to dispense food, a new tool for use in behavior testing and behavior modification for dogs.


The genesis of the Feeder Hand concept and design of the prototype.

the original Assess-a-HandTM and its use

Some years ago the innovative shelter opperator and shelter dog advocate Susan Sternberg, <www.suesternberg.com> , developed a method of testing dogs for food bowl aggression without endangering the hand, arm, and face of the testing person. For this purpose she invented the "Assess-a-HandTM" , a costume store vinyl or latex hand and arm mounted on a wooden dowel. I consider this to be an absolutely brilliant invention, as it allows testing the dog without risking a bite to one's own tender flesh.

Sternberg's food bowl guarding test proceedure is to have the hand approach the dog's face as the dog is eating and then have the hand reach into the bowl. This is obviously something that could be very risky to do with your own flesh and blood hand, as it puts hand, arm, and face in line to be bitten if the dog reacts aggressively. In a shelter situation, you can be sure that you will encounter some dogs who do react with a swift bite. In Sternberg's test, which I have seen done to several dogs on videotape, she approaches the hand to the bowl and if the dog shows aggression, the hand retreats. This is repeated several times. The same test is also done with a "higher value food treat" such as a pig's ear, a rawhide chew, or a bone.

problems with Sternberg's method of testing

Now I recognize and fully applaud the idea of testing a dog for food bowl and higher value treat guarding before the dog is offered for adoption. Much better that a fake hand get bitten than that the adopter or adopter's child or guest get bitten. So Sternberg's use of a fake hand instead of a real one is a genuinely brilliant innovation. BUT when I saw that in the proceedure of the hand approaching and then retreating if the dog aggressed, I noticed that when this was done in several repetitions, if the dog had shown some aggression on the first approach , the dog would become more aggressive on each sucessive repetition. So what is the dog actually learning from this series ? It seems to me that the dog is learning that being aggressive to the threatening hand (hand that dog percieves as a threat) will make the threat go away. The dog is learning that an aggressive response works, ie is rewarded by the desired consequence of the hand leaving. The dog is learning to be more aggressive in guarding food. That is making the dog more dangerous and less adoptable and in many cases results in the dog being euthanized without ever being tested for whether or not the dog is capable of changing its attitude to a better one.

genesis of the Feeder Hand

So I started thinking about a better way, a way that would allow the dog to begin learning that the hand was there to give rather than to take, that would allow the dog to begin to learn that an approaching hand is a good thing and should be welcomed. Thus I wanted a hand that could dispense food, a hand from which food could be released when I chose to release it. In my mind , I called this "Assess-a-Hand II" or "Assess-a-Hand, the Next Generation" ; but since the term "Assess-a-HandTM" is trademarked, I am now calling it "Feeder Hand." or it could be called "the Feeding Hand" or "The Hand That Gives Goodies". I will not seek a patent or a trademark for this invention, nor do I intend to produce them for sale. I encourage everyone to make their own, and I offer several plans for doing so.

The fake hand and arm were no problem. I phoned a few local costume stores to ask about fake hands. The hand pictured on this page was obtained from a local store for $10 ; they had one with just the hand for half of that, and also had a similar one that cost twice as much without being any better suited to the purpose. I also did a Google search and found a number of on-line costume store sources that had various types of hand and hand-arm combinations with reasonable prices. The best place to find these at lowest cost is to visit any Halloween stores the day after Halloween , when there is likely to be a half-price clearance sale.

I already knew about several grasp and release tools which can be obtained from hardware stores and other sources. There is the several foot long tool that has a plunger on one end and a small clawed gripper on the other, the griper opening when the plunger is depressed and closing when it is released. Very useful for picking up small items that need to be retrieved from hard to reach places, such as a screw dropped into an automobile engine compartment. This tool sells for a very few dollars, so it was the first one I tried. The tool is run under the "skin" of the vinyl hand and arm so that the gripper emerges in the palm of the hand through a small cut in the vinyl. My prototype Feeder Hand, which is pictured above holding a piece of chicken jerky (the brown thing held in the palm), is of this design.

The hand or hand-arm are mounted on a wooden dowel, thus putting your own body further away from the dog's mouth. For my prototype , I just stuck a short dowel a small way into the arm. For an improved version, I pulled out enough of the arm's stuffing to allow the dowel to be inserted deeper and I used a longer dowel.

Potential uses of the Feeder Hand

The Feeder Hand potentially can be used in any situation where you need to test a dog's reaction to the approach and/or touch of a human hand. While an artificial hand does not smell anything like a real human hand, a dog who is aggressive enough or fearful enough to bite a human hand, especially to do so in a suden fashion without first escalating through the warning phases of posture, growl or snarl, and bared teeth before actually snapping or biting, is probably going to react to the fake hand enough to let you know that you've got a problem that you do not want connecting with your real flesh and blood. The dog who is thoughtful and unreactive enough to notice that this is not a real hand is probably not the dog you have to worry about, ie is not a "reactive" type of biter.

In addition to testing for food guarding or toy guarding, you may also want to experiement with using the hand in testing for such problems as the following :

my testing method

When testing with the Feeder Hand if you get any kind of beginning of a fearful or aggressive reaction, eg if the dog freezes or stiffens slightly, try to neither increase the approach nor decrease it. Calmly wait for several heartbeats , observing the dog, preferably by periferal vision rather than a direct stare. If the dog relaxes even the tiniest amount, release the food to him. As he catches scent of the food, he may very well relax slightly, and that gives you and oppertunity. But if necessary, slowly withdraw the hand until the dog does relax and at that point release the food. Make the next approach slower and less close, so you can release the food before the dog tenses up. Make a number of these non-tension producing approaches and release food to the dog. With luck, after a half dozen approaches you may see a slight change in his willingness to have the hand approach. Quit on a good note ! At this point your testing has revealed that yes, there is a problem, but , good news, there is reasonable hope of improving or curing the dog's attitude by desensitization and counter-conditioning. The half dozen non-reaction-producing approaches you have just made are the first desensitization series , and the releases of food are the first counter-conditioning series.

protocol for cure of food guarding

The process of using the hand for cure of a problem through desensitization and counter-conditioning is simply more of the same. As the dog gets more accepting of an approach at very slow speed and to a not very close distance, one can begin to very very gradually make the approches a bit less slow and a bit closer, but never pushing it enough that the dog tenses up. Release the food before the dog can react tensely. You are rewarding him for remaining calm and you are getting him to associate the hand with good stuff thus with happy feelings. (A behaviorist might be discussing the concepts of "operant conditioning" and "clasical conditining" here, but what is important is that the dog learn that the hand is not a threat but rather something nice, so he learns a welcoming emotion instead of a fearful or aggressive one and an overt behavior of not retreating or biting but rather doing something benign.) At some point you may also start asking him to Sit before you release the treat. You can use the treat in the hand to get him to lift his nose up and rotate his head backwards, ie so nose is pointing at the sky. This will usually cause a dog to sit in order to make himself comfortable with head in that position. You can also use the hand to coax him into a Down by lowering the hand to the floor to lure his nose down to the floor and forward between his feet.

When the dog is completely accepting of a variety of approaches by the Feeder Hand, including fast approaches from above the dog's head (which dogs can find threatenting or challenging), you may be ready to start working with your own real flesh and blood hand. At this point you want to take many giant steps backwards and begin the sequence all over again beginning with very slow and not very close approaches , dropping the food while the dog is still completely calm or happy. Do not be in any hurry to make progress, because any mistakes can be very painful.

For some problems , you might find that the dog never does get to the point where you want to risk your own flesh and blood. That is the time to re-evaluate the issue of adoptability. Is it possible to "manage" the dog's life in such a way that oppertunities for a situation to trigger a bite can be completly prevented ? In some cases this is really easy. Eg if the dog only guards high value treats, then either never give him such treats or give them only when the dog is crated or in an X-pen, and pick up any remnants with long handled BBQ tongs. If the dog guards his dinner bowl while eating, feed him in crate or X-pen. If the problem is one that an intelligent and self-controlled adopter could effectively "manage", then it may be possible to find such an adopter. The adoptive home cannot however contain any resident children of less than adult level judgement, because children tend to act impulsively. (Occasional visiting children can be "managed" by crating the dog during the visit or putting it in a boarding kennel.) If the foster home really likes the dog a lot and is committed to "managing" the problem safely, then adoption by the foster home may be the very best solution(as I did with "Shady, who was a wonderful dog in every other way). However if the problem cannot be "managed" and the dog has the physical power to hurt someone seriously, it would be time to admit defeat and euthanize the dog if you are unable or unwilling to keep the dog yourself. .


the "Pickup Hand" that can pick up a bowl

I really would have liked a tool that had the ability to pick up and set down a bowl with dog food in it. There is a tool sold under various names that can pick up things such as soda cans ; this is used by park clean-up crew, by people in wheelchairs to reach stuff otherwise above or below reach. Unfortunately the ones I have seen won't insert inside the fake hands and hand-arms that are currently on the market. Also they cost $20 to 30, which would puch the price of a commercial version up higher than I wanted , though still very cheap if it prevents even one bad bite from landing on someone's real flesh !!! .(UPDATE see below, there is a less sturdy but very cheap version of this tool. If you are impatient, click cheaper).

However I have a prototype of Pickup Hand that is made with an ordinary kitchen tong (available cheaply at most thrift stores) with handles unbent and inserted into the thumb and either ring finger or longest finger of the hand. See picture below, in which the unbent tong is laid on top of the hand, and the picture of the hand holding a very small bowl. The costume hand used in this prototype is the same one used in the Sternberg "Assess-a-HandTM". I got 4 of these for $5 at a Halloween Store half-price close-out sale the day after Halloween. You can find them on-line for about $10. To make this hand useable, as in the photo of the hand grasping a small bowl, I would insert the tongs into the hand after using dowels or flat sticks (paint stirring sticks obtained free at the hardware store are shown in the photo), then (for a finished product) re-stuff the arm with the cotton it was originally stuffed with and sew the sleeve-end closed. This does require a fair bit of work and a bit of sewing skill, but most people could do it.

The finished prototype has the tong tips inserted into thumb and first finger of the hand. The other end is attached to 3 foot long dowels, thus letting the opperator be more than three feet away from the dog's mouth. This is the prototype shown in the companion article "The Feeder Hand in Action ".

How to construct a Pickup Hand that can pick up a small dog food bowl

The Pickup Hand holding a small dog food bowl

an easier way to make a feeder hand

I came accros an inexpensive pick-up tool at Dollar Tree. All you'd have to do to make a Feeder Hand is to strap (plastic zip ties ?) this tool to a costume hand and arm (or to an Assess-a-HandTM if you already have one). You might want to insert a dowel intside a costume arm to improve the firmness, ie thus turning costume arm into an Assess-a-HandTM, then attach the pick-up tool. I include an illustration of the component parts. For home use this inexpensive grip tool should suffice, but for shelter use a more robust version from the hardware store might be worth the higher cost ($25 to30) because of greater durability

costume hands and DollarTree grip tool

Caution :

All of the above suggested behavior modification methods are simply suggestions, based on established principles of behavior modification. I have NOT had chance to test these methods extensively. In any case, the success of any behavior modification method depends upon the skill of the person doing it. Any work conducted with a dog who has shown any indications of threatening to bite MUST be conducted with great care for your own safety. This kind of work has very real risks, but the work may be the only oppertunity to change the dog's behavior and save its life. I think the use of any kind of fake hand is less dangerous than equivalent work done using your own real flesh and blood hand, but please keep in mind that "less dangerous" does NOT mean that it is SAFE !!! You can still get hurt if you get careless, rush the training, or simply don't have enough dog skills.

related articles :

site author Pam Green copyright 2003
created 12/27/05 revised 10/25/2014
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