The Right Way to Use Desensitization and Counter-Conditioning to Help a Fearful or Aggressive Dog

Photo by designerpoint

When it’s done right, this method is a beautifully effective and long-lasting solution to a wide variety of fear-based behavior problems. Unlike methods that only suppress the dog’s reaction (which is really just a symptom of their fear), you’re getting inside the dog’s head and changing the way they feel about the whole situation.

It can help with dogs who are:

  • Reactive/leash aggressive
  • Food aggressive or possessive of certain objects
  • Afraid of men/children/people with hats, etc
  • Upset about a new baby or new animal in the household
  • Afraid of vacuum cleaners or other loud scary objects
  • Afraid of having their nails trimmed

This method is not the only possible solution to these problems, but it’s a good solid place to start.

It means teaching Sparky that the presence of the Scary Thing (other dog, vacuum, child, nail clippers, etc) means Sparky gets something good: “When I see a dog down the street, treats rain from the sky! I LOVE the dog down the street.”

To which half of our readers just responded:

“I tried that and it didn’t work.”

There’s a good chance that if you’ve been struggling with your dog’s issues for a while, you’re at least somewhat familiar with the whole “feed treats when the dog sees the scary thing” thing.

And let me guess: you’ve had limited success, at best.


See, dog training is a mix of art and science, but the portion of dog training known as desensitization and counter-conditioning is ALL science. Super technical. There is a distinct order of operations that must be followed, and a set of rules that can’t be broken. If anything is out of place, then yeah, it won’t work.

Don’t let that scare you away, though. As technical as it is, it’s also very simple once you really understand it.

This article will show you how to get it right, and how to avoid common problems that lead to “I tried it and it didn’t work.”

Let’s make it work for you.

The method in a nutshell:

Desensitization means gradually exposing a dog to the stimulus (aka the Scary Thing) in doses that are small enough that the dog doesn’t react negatively. The dog gradually becomes less sensitive (i.e. less scared, less reactive, less angry) to the stimulus.

Counter-conditioning means changing the way the dog feels about the Scary Thing, so that it becomes at the very least a Neutral Thing, and preferably even a Good Thing.

These tactics are often best used in combination with each other, which is why we’re referring to them as one method, DSCC for short.

Three Factors for DSCC Success

1. The all-important Conditioned Emotional Response (CER)

We all have conditioned emotional responses where some stimulus triggers a particular emotion in us. Think of how do you feel when:

  • You hear your alarm in the morning
  • You see a spider in your house
  • You see a cute baby animal
  • Your boss approaches your desk
  • You smell your partner’s cologne/perfume

The way you suddenly feel when each of those stimuli (alarm, spider, etc) occur is your CER. The point of DSCC is to change the conditioned emotional response the dog has toward the trigger.

For example, a dog with food aggression: A human approaching the dog’s bowl is the stimulus, or trigger. The dog’s CER is fear or anger. “Oh no, they’re gonna take my stuff!”

We want to change his CER to happiness. “Yay, they’re going to give me something good!”

Most people get this part, in theory. But oftentimes, they don’t wait for the appropriate CER to develop. This is one of the reasons DSCC doesn’t work for them. They’re not making sure the dog is actually developing a positive CER at each level before moving on to the next level.

How do you know when you’ve successfully created a positive CER?

True fact: my wife Erin’s dog, Bear, used to be severely dog-reactive. Erin has done a fantastic job of rehabilitating his reactivity. He’s not 100% non-reactive now, but he’s pretty damn close.

On my most recent visit to Erin and Bear (my wife and I don’t live in the same country yet. Long story), she told me about a specific trigger of Bear’s: two barky little dogs who live down the street. Bear used to get upset whenever he was walked past their yard. So Erin started giving him treats every time they saw the barky little dogs.

One day, I took Bear on a walk by myself. When we approached their yard, sure enough, the barky little dogs appeared and began barking. Bear looked back at me, with a quick wag of his tail and a happy expression: “Okay human, this is when you’re supposed to give me treats!”

That’s a successfully created CER.

Since we can’t know exactly what a dog is feeling on the inside, we rely on body language. Watch how the dog reacts when the stimulus appears. You’re looking for soft, happy body language. When Sparky looks up at you as if to say “there’s the trigger! Where’s my treat?” You are ready to move forward.

Free online course: Dog Speak 101

This video course from the 3 Lost Dogs Academy will teach you all about canine body language. You’ll learn how to recognize soft/happy body language, and how to tell when a dog is stressed. Click here to check it out!

2. Work under-threshold at all times

What is a threshold? It’s the line between two states. When you move through the threshold of a door, you move from one room to another. Behaviorally speaking, it’s moving from one emotional state to another.

The most commonly used threshold example is that of a reactive dog. The moment the dog goes from being relatively okay to barking, snarling, and lunging is called going over-threshold.

But there are other kinds of going over-threshold.

For the more timid dog, over-threshold might be cowering and shaking, or trying to run away. When I took my shy puppy River to the vet for the first time, she flattened to the exam table, closed her eyes, and “shut down.” Poor girl was WAY over threshold.

There’s no hard-and-fast rule about where the threshold line is for any given dog, so here’s a handy guideline you can use: the moment the dog exhibits the problem behavior (the behavior that led you to read this article) they have gone over-threshold.

When working on fearful or aggressive behavior, always work under-threshold. You don’t need or want the dog to exhibit the problem behavior in order to change it. The more the dog hits their threshold, the longer it will take to solve the problem.

When a dog is over their fear/aggression threshold, their body has fired up the fight/flight/freeze response. They’re not in a place where DSCC can work. Throwing a handful of the world’s most delicious treats in the face of a dog who is snarling at the vacuum cleaner will have zero effect.

The goal of training is to raise the dog’s threshold. For example, Zeus the Dog-Reactive Dog’s threshold might currently be seeing the distant speck of a strange dog a block away. With training, we’ll raise that threshold to seeing a dog half a block away, and then five meters away, and so on.

There are many points along the way to hitting threshold. Unless the trigger catches them completely by surprise, a dog doesn’t go straight from being happy and carefree to freaking out.  For example, here are signs a reactive dog is approaching their freak-out threshold:

  • A fixated stare – Ears forward, body pointed straight at the trigger.
  • Raised hackles – this is involuntary, like goosebumps. It’s a great indicator of your dog’s internal state.
  • Increasingly frantic movements – Sparky may dart back and forth, “tap dance” with his front paws, or bounce up and down.
The sweet spot:

The point where the dog is aware of the trigger, but not upset. That’s where you want to work at all times.

A quick test to make sure your dog is in the sweet spot where DSCC will be effective: the dog will take high-value treats the same way he takes treats when he’s hanging out in your kitchen, hoping for scraps.

If he refuses the treat, or if he takes the treat more frantically than normal, accidentally hurting your fingers, he’s too close to threshold.

3. Make sure you get the order of operations right

For DSCC to work, the stimulus must appear before you present food. Not after the food. Not even at the same time as the food.

Whatever comes last in the sequence of trigger-and-food is what your dog will base his emotional response on. You want Sparky to learn that the presence of the trigger predicts treats. You don’t want Sparky to learn that the presence of treats predicts the presence of the trigger.

Here’s a helpful thought experiment: imagine you’re seven years old, and you hate going to the doctor. But if your parent takes you out for ice cream after every appointment, you might start to look forward to doctor visits! But what if your parent takes you out for ice cream before your appointment? You’re sitting in the ice cream shop, eating your waffle cone, still dreading the appointment. You might grow up to hate ice cream.

Make sure you get your training “mechanics” real clean. Wait to reach into the treat container until after the trigger has appeared. People have a tendency to reach for the treats in anticipation of seeing the trigger, but trust me, the dog notices you reaching. He might learn to go on guard when he sees you reaching for treats, because it means that hijinks are afoot and the dreaded trigger is SOMEWHERE around here.

Of course, there’s an obvious problem: you have to get your treat container and training gear set up before you begin a session of DSCC, so won’t the dog learn that you setting up your gear means the trigger is near?

That’s certainly possible. So I would make sure that I’m doing a lot of other training that involves treats, not just DSCC. Like obedience or trick training. So the dog learns that the training gear setup can predict a wide variety of fun activities. It’s not solely associated with scary triggers.

And if you’re working on DSCC at home, you can sneakily set up the gear when the dog is not in the same room.

For best results when working outside the house, get a wearable treat pouch. That way, you don’t have to juggle a container of treats in your hand and muddle up the order of operations.

For even better results, practice your training mechanics in situations where the trigger isn’t present. Do a practice scenario in your living room. Enlist a friend or partner or child to pretend to be the trigger.

For bestest results, film your training sessions. You may discover you’re getting the order of operations sliiightly wrong, or realize you have a particular “tell” when you’re about to reach for the treats.


Photo by Frank Pontier

1. Determine the distance/intensity at which the trigger can be present while keeping the dog under threshold


Fifi the Vacuum Hater needs the vacuum turned off, in the next room, visible through the doorway.

Zeus the Dog-Reactive Dog needs the trigger dog a full block away.

Athena the Mildly Dog-Reactive Dog can handle the trigger dog being just across the street, as long as the trigger dog is standing still and facing away from her. A dog moving and looking at her is too intense for now.

Hercules the EXTREMELY Dog-Reactive Dog cannot handle dogs being visible at all. Just walking around outside his house, where past experience has taught him that dogs may appear, is his sub-threshold sweet spot.

There will probably be a little bit of trial and error to figure this out. That’s okay, just don’t begin the DSCC training until you’ve got it.

2. Present trigger. Feed chicken or other high-value treat


Fifi the Vacuum Hater: an assistant rolls the vacuum into view. Fifi’s human feeds her a continuous stream of chicken.

Zeus the Dog-Reactive Dog: Zeus and his owner take a walk on their street, his owner keeping a watchful eye for dogs. When a dog appears down the street, owner feeds Zeus a continuous stream of chicken.

Athena the Mildly Dog-Reactive Dog: an assistant has their well-behaved dog sit and eat treats. Athena’s owner walks Athena into view of the assistant dog and feeds Athena a continuous stream of chicken.

Hercules the EXTREMELY Dog-Reactive Dog: After making sure the coast is clear, his owner brings Hercules into the front yard and feeds him a continuous stream of chicken.

3. Remove trigger, stop feeding

Fifi the Vacuum Hater: after ten seconds, the assistant rolls the vacuum out of view. Fifi’s owner stops feeding treats.

Zeus the Dog-Reactive Dog: after ten seconds, Zeus’s owner walks Zeus out of view of the dog down the street, and stops feeding treats.

Athena the Mildly Dog-Reactive Dog: after ten seconds, the assistant and Athena’s owner walk their dogs out of view of each other, Athena’s owner stops feeding treats.

Hercules the EXTREMELY Dog-Reactive Dog: after a minute (longer than the others because the “trigger” is less acute), Hercules’ owner walks him back in the house and stops feeding treats.

Repeat steps 2-3 until the dog develops a positive CER.

4. Increase the intensity of the trigger and repeat

There are a few ways to make the trigger more intense:

Distance: decrease the distance between your dog and the trigger.

Duration: stay in the presence of the trigger longer.

Sound: turning the vacuum on, the trigger dog barking, etc. If the dog is afraid of humans and you’re working with a trigger human, having the trigger human talk.

Movement: the vacuum moving back and forth. The trigger dog walking around, or the trigger human swinging their arms.

Every time you increase one of these intensifiers, you temporarily decrease the intensity of all the others.

When you first turn the vacuum on, you increase the distance – put it in the other room with the door closed so Fifi can’t see it.

For Athena the Mildly Dog-Reactive Dog, when you have the trigger dog move and face her for the first time, have them be farther apart than normal. When you have the trigger dog bark, make sure they’re WAAAY farther away than normal.

When you move the trigger human closer to your human-fearful dog, have that person decrease their intensity factor by sitting down, or facing away, or both.

Hercules the EXTREMELY Dog-Reactive Dog: having a trigger dog enter the picture is still too much for poor Hercules, so his owner has an assistant bring in a life-size stuffed dog. Later, they can level-up to having a trigger dog appear WAAAY off in the distance.

Common Mistakes

Getting the order of events wrong

Really focus your efforts on making sure the trigger happens before food is fed to the dog. Remember how I suggested setting up pretend situations where you can practice, and filming your training? I was serious about that.

Using treats that aren’t good enough

You need something super delicious, like real chicken. Something your dog really loves. Mediocre dog biscuits may not be powerful enough to change the CER.

Being too stingy with the treats

When I say “feed a continuous stream of treats” I mean like one treat every 1-2 seconds. They don’t have to be big chunks; small pieces work just fine. Just make sure it’s a steady stream.

Trying to train when the dog is too close to threshold or over threshold

If the dog is growling, trembling, staring intensely at the trigger, raising their hackles, or just too tense to take treats, you’re too close to threshold for training to be effective. You want your dog in a nice chill state. If you find yourself thinking “nothing is happening! We’re too far away from the trigger, Sparky isn’t bothered.” then you’re exactly where you need to be. Patience, grasshopper. Err on the side of caution. Better too far away from the trigger than too close.

Not waiting until the CER is established before leveling up

This might be the most common mistake. You really need to take your time, do plenty of repetitions, lots of training sessions, and make sure your mechanics are nice and clean, so that a positive CER develops at every level of training.

Something that often happens: owner does a couple sessions of DSCC at a low level, and Sparky technically isn’t going over threshold, but he’s not happy about the trigger yet. He’s still very tense, and you can tell he’s thinking about growling. But because he’s not hitting threshold, the owner takes that as the green light to increase the intensity of the trigger. Which turns out to be too much for Sparky and he explodes.

Train at a low level of intensity until Sparky shows happy body language in the presence of the trigger.

Having the scary person feed treats

If your dog is afraid of people, it might seem like a good idea to ask those people to give your dog treats themselves. And for sooooome dogs, it can be. But it often makes things worse: focused on the treat, the dog approaches the person. Once they eat the treat, they suddenly realize they are VERY CLOSE to a scary trigger! Oh ****! Now they’re more startled than they were before.

So when you’re working with “scary people,” feed the dog the treats yourself. You can eventually start having people toss treats to your dog, so Sparky doesn’t have to approach them.

Asking for a behavior to reward/confusing operant and classical conditioning

With operant conditioning, you reward specific behaviors: “Sparky, sit! Good dog. Here’s a treat.” With strict DSCC, you’re not rewarding behaviors. Sparky is not required to sit, or make eye contact with you, or do anything else to earn the treats you’re feeding him. It can be confusing, because some good methods for helping fearful dogs do reward specific behaviors. But when you’re doing the straight up DSCC thing, you don’t.

So there ya have it, the basics of good DSCC mechanics. Please note this isn’t a full and complete plan for helping dogs with complex issues.  Usually after a dog has had some success with DSCC, we’ll use operant conditioning to teach the dog appropriate ways to behave. And depending on the specific issue, DSCC is usually used in conjunction with other tactics, like management, an appropriate exercise plan, or in some severe cases, medication.

Also check out:

Do you know what your dog is saying?

Understanding the subtle ways dogs communicate is a critical skill for dog owners. It can help with choosing the right dog, solving training problems, and building a strong bond.

This free video course from our online academy will give you a basic, yet detailed, introduction to the wonderful world of canine body language and communication.

Want our help?

Follow us:

You might also like: