The anxiety cascade: why uncertainty can affect our dog

In the last ten years, it’s become more important to view anxiety and fear as different phenomena.

In the past, they were seen as ‘shades’ of each other. They meant almost the same thing. In fact, we could think of them as synonyms for each other. Anxiety might have simply been a less dramatic version of fear.

In the veterinary behaviour world, most researchers take these two terms as being different.

Anxiety is what’s known as an antecedent state. What that means is that it comes before anything actually occurs. We feel anxiety about things that haven’t happened yet.

If our dog has separation anxiety, the anxiety part is a concern that separation might occur. It was the emotions our dogs experienced before we left. That feels at odds with how we use the term, because separation anxiety is often what we think of when considering our dog’s actual panic after we have left.

Fear, on the other hand, is a postcedent state. It happens after something scary occurs.

Up until around 2016 or so, this lack of clarity didn’t really matter. “Separation Fear” or “separation panic” didn’t sound as catchy as “separation anxiety” anyway.

In 2016, however, two highly influential papers were published that made it increasingly clear that veterinary behaviourists were right to make this distinction. That anxiety comes before things happen and fear comes after was the focus of a paper by Professor Joseph Ledoux. This was supplemented by a paper by Lebow & Chen about the role played by a part of the brain called the “extended amygdala” which is involved in many processes, notably anxiety.

How anxiety and fear differ

Anxiety is an anticipatory emotion connected to arousal levels. It comes before anything happens.

But why would an individual feel anxious that something might happen?

The first is a learning history.

If it’s predictably happened before in a particular location or under a particular set of circumstances, it might happen again. Best be on guard.

The second is situations of uncertainty.

When things get unpredictable, we are on higher alert than in situations of predictability. New places, changes in routines, unexpected things… they all create uncertainty and unpredictability. We’re simply more on guard than we would be in familiar circumstances.

This even causes effects on our sleep. You may have experienced it if you’ve slept less deeply in a new place. We’re much more easily roused in new sleeping locations than we would be in our own beds. This is true as long as our own beds are safe and quiet places to be, of course. If you’re sleep-deprived, a new bed in a new location might give you some much-needed catch-up! Even when we are asleep in novel circumstances, we’re not quite as restful as we would be otherwise.

Habituation and sensitisation

You may notice that it takes your dog a little time to relax in new places. Unless they are chronically sleep-deprived, of course!

On the other hand, fear is a response to something that has already occurred.

That can involve a startle response. It can also involve sensitisation. Sensitisation simply means that we temporarily respond with a much more intense response than we would normally. Habituation is the opposite of this process. Habituation means that we simply ‘get used’ to things.

As an example, one of my neighbours is a farmer. Because he is often out and about in his tractor, I have habituated to the daily tractors passing. I simply don’t notice it anymore. However, a guest came to stay recently and she became very sensitive to the tractor noise. She noticed it more and more over time and found it increasingly disruptive.

The same things can happen to our dogs. On one walk, we pass a field. Sometimes there are sheep in there, and sometimes not. Although she is generally good around sheep these days, my dog Lidy sometimes sensitises to them temporarily.

Why do mammals habituate or sensitise?

This question has been a central one for research. After all, unwanted sensitivity is something we’d all want to avoid, I’m sure!

Several things seem to contribute to the likelihood we’ll get used to things that were noticeable at the beginning. One of those things is the strength of the stuff we’re experiencing. It’s easier to habituate to things if they are mild. This is true whether it causes excitement or whether it causes fear.

For me, the distant hum and rumble of tractors is very far away and that helps me get used to it. The first one my friend heard was very close to the house and even made the windows shake. Where I still noticed that one, I didn’t sensitise to it even though it was noticeable.

Another thing that makes a real difference is our mood state to start. The more aroused we are physiologically, the more likely we will be to sensitise rather than get used to things.

Sensitisation doesn’t care if those are positive emotions of expectation or negative emotions of anxiety: if you are prepared for something to happen and you are in a heightened emotional state, it means we’re more likely to sensitise.

It probably didn’t help my friend that next door’s dog startled her as she got out of her car. Because she was already sensitive, on edge and in recovery from that initial fear response, when the tractor rumbled past, it made it more likely she would sensitise rather than habituate.

Emotions and sensitisation

Arousal certainly makes it more likely we’ll have a super-strength reaction. But anticipatory emotions do as well. This is where the work of Ledoux and the work of Lebow & Chen comes in.

In uncertain or new situations, we may feel excited or we may feel scared.

For humans, that often depends on context as well as our natural biases and personality traits.

For me, I love new places and I love travelling. I remember arriving at a hotel in the heart of Fes in Morocco. The first moments in the medina in those tiny alleyways were wonderful. In that sensitive state, the smells of spices, of oranges, all the sights and movements and activity was quite delicious. I’m a confident person on the whole and going in to new situations is exciting for me.

This makes me likely to sensitise to things in that world.

But anxiety also makes us sensitise in the same way. Being prepared for the unexpected heightens our arousal levels. Think of the body as being primed with noradrenaline and adrenaline, ready to go if necessary.

Anxiety and sensitisation

As you can see, my strongly exploratory and curious nature (and a long history of reinforcing travel experiences!) makes those first moments in a new place utterly divine. My senses are heightened. Food tastes more delicious. Colours seem more vibrant. It feels like the world is in technicolour and Dolby surround sound.

I would be just as likely to sensitise to things as a friend would who is highly anxious.

Another friend came to stay with me and we took a trip to Paris. He feels quite unsafe in new places and as soon as we arrived at the large and busy train station, he was already on edge. His extended amygdala was doing its job, keeping him ready to respond. He was in a state of high alert and anticipation that something could happen.

On the Paris Métro, there was a man behaving a little oddly. I thought nothing of it, noticing the vibrant flowers another person was holding, all the amazing and vivid reality of Paris. My friend, however, was very alarmed by this individual and as a consequence, he refused to go back on the Métro the next day.

Being in a state of anxiety makes it much more likely we will sensitise when something intense and unexpected occurs.

For our dogs

The same principles are at work for our dogs. Imagine our anxious dog in a busy city dog park.

They may already be anxious before they go in.

This is especially true because a dog’s sense of anticipation is heightened through smell. Odours let us know to be on guard, but they don’t always tell us where the source of those odours is, or how long it has been since they were there.

Now dogs are good at discriminatory sniffing, able to notice directionality. They will know where the source of those unfamiliar odours is. They are also good at getting temporal information from odour: how long it is since those odours were deposited?

Without being able to ‘read’ odours, our dogs would never be any good at mantrailing or scentwork. These activities require dogs to identify more dense clusters of odorants compared to less dense clusters.

The location and context may be ones that have previously predicted unpleasant experiences. For that reason, it may put our dogs on edge just in case. It acts to prepare them just in case. Here, learning history can cause arousal and anxiety that can help our dogs avoid bad experiences.

However, new places can also affect our dogs. Because they are uncertain and unpredictable, new events, experiences and locations can cause initial anxiety until our dogs have settled a bit and feel more confident.

If something happens in those situations, it can make it more likely that our dogs will have a reaction that is bigger than normal.

The cascade that follows

For anxious dogs, they are simply waiting for the world to confirm that their expectations were accurate. When things occur that cause them to react, it simply confirms their belief.

We can think of that belief strengthening each time there is a confirmation. All that happens is our dogs learn that they were right. All anxiety does in those situations is confirm the necessity of preparedness and vigilance, even if it wasn’t very helpful. It may also contribute to much larger reactions from our dogs.

Prior anxiety can heighten fear responses, making them more intense, last longer or become more frequent.

In turn, this makes it more likely that our dogs will learn the subtle cues that predict the likelihood of scary situations. If our dogs have been repeatedly sensitised, it also makes it more likely that they’ll sensitise again to the same things at a later date.

Where we normally get used to things eventually and sensitisation is temporary, the problem for our dogs is that they can pick up on subtle clues that predict scary stuff, including the risks of going into new places.

Then, they learn behaviours that work to help them avoid those situations in the future if possible. For instance, they may try to avoid going into the dog park if that’s where bad things happened in the past.

How sensitisation contributes to avoidance

Avoidant behaviour can be very, very difficult to overcome. It is very persistent behaviour, and the temptation is often to force dogs to experience things so they will ‘get used’ to them. Meanwhile, because this creates anxiety, it just makes it more likely that even if something very mild happens, our dog will have a heightened response to it.

It becomes a vicious circle. If our dogs are anxious that bad things might happen, if they do, then it confirms their belief. If our dogs are anxious, it also makes it even more likely that should something unexpected occur, they’ll be more scared by it than they might have been otherwise.

One solution to this in the past has been very gradual, gentle exposure. One problem with this is that it can put our dogs into persistent states of chronic anxiety if we have no way to let them know that the bad stuff definitely won’t happen.

This makes treatment difficult.

One way to resolve this dilemma is to teach specific safety cues. These help dogs understand when bad stuff will or won’t happen, and lowers their anxiety. They can also be used to help dogs re-experience events so that they can downgrade them from ‘very scary’ to ‘tolerable’ or even ‘not scary at all’. This webinar on safety cues explains the science behind them.