Stress stacking and stress endurance

Have you wondered why sometimes, your dog reacts in situations she usually doesn’t react in? Why sometimes, she lunges at a passing cyclist, and other times she doesn’t? How sometimes she barks at running children, while usually she notices them, but seems okay with it? How usually she’s fine with passing a strange dog, but sometimes barks and snaps at him? 

We tend to assume that a stress diagram looks like this, even when several potential triggers happen simultaneously:

Graphic 1: one potential trigger at a time

Unfortunately, this diagram only depicts your dog’s (lack of) reactivity when encountering one potential trigger at a time. If your dog is slightly excited by cyclists, slightly worried about running children, and just a little concerned about meeting strange dogs, neither of these potential triggers will take your dog over her threshold when encountered on its own (graphic 1).

However, what happens if there is more than one trigger? Rather than not affecting each other, stress levels pile up when happening simultaneously. Grisha Stewart calls this phenomenon “stress stacking.” Consequently, the diagram looks like this:

Graphic 2: stress stacking (several triggers simultaneously)

Imagine you and your dog are walking past a playground with children playing, shouting and running. If a cyclist passes the playground at the same time that a strange dog walks towards you, your dog’s stress levels stack up and she is pushed over threshold by the combination of triggers (graphic 2). 

Challenging environments and default stress levels

Stress levels are not only individual triggers. Challenging environments (e.g. an agility trial environment, a dog show environment, the vet’s office, a busy city center etc.) have a higher default stress level (DSL) than everyday life. Hence, in a challenging environment with a high DSL, it takes less triggers to put your dog over threshold, or she may be pushed over threshold by one individual trigger she normally isn’t reactive about.

Imagine walking your dog past the busy playground of our first imaginative scenario. A strange dog and his owner walk towards you, but there is no cyclist and there are no other distractions. Your dog will be fine; the combination of children and dog will stress her slightly, but won’t put her over threshold. 

However, imagine you are taking your dog to see the vet. The vet’s office has a higher DSL than everyday life. If there isn’t only a strange dog in the waiting room, but also a mother whose children are playing catch, your dog will be pushed over threshold by the same two triggers she could deal with outside the vet’s office (graphic 3).

Graphic 3: default stress levels (DSL) in challenging environments 

For some fearful dogs and many young puppies who are just getting to know the world, a foggy day, dusk, dawn or darkness may constitute a challenging environment as well: silhouettes and shadows look different at night than during a day, and many puppies have to get used to this before they are okay with it.

The time factor

Stress levels are not only affected by triggers present at the moment, but also by things experienced a little earlier. In fact, the adrenalin level in your dog’s body (as well as in your own body, for that matter) reaches its peak 15 to 20 minutes after a stressful event rather than right away. The testosterone level goes hand in hand with the adrenaline level and also peaks 15 to 20 minutes after a stressful event.

Furthermore, it takes a while for a dog’s (or human’s) nervous system to calm down again. Depending on the intensity of the stressful experience, the adrenalin level may take up to a week (!), the cortisol level up to 40 days (!) to go back to normal (graphic 4). (1)

Graphic 4: the short- and long-term development of hormone levels

Hard to imagine? Let’s look at another example (this example was suggested by Anne Lill Kvam during a dog trainer seminar last weekend): imagine you’re driving home from work, and someone takes your right of way. A little later, the same thing happens again. You’re slightly annoyed, but glad you avoided an accident. 15 minutes later, you unlock the door to your apartment and are greeted by your girlfriend with the words: “you didn’t forget the groceries, did you?” This innocent question puts you over threshold because your adrenalin and testosterone level have just reached their peak, making aggressive reactions more likely.

Practical implications

– Be patient – with yourself, with your dog, and with others. They probably can’t help their behavior: their hormone levels might be agitated. 

– Remember the importance of giving your dog frequent breaks, especially in stressful situations. (And give yourself breaks, too.)

– Introduce one new stimulus at a time when training new behaviors. 

– Lower criteria when practicing a new behavior in a challenging environment.

– If you have a performance dog, work on lowering the default stress level in challenging environments (such as the agility trial environment) in order to maximize performance. This should be done separately from working on other behaviors such as agility obstacles. Keeping the DSL low in challenging environments is an independent skill-set and should only be combined with other tasks after it has been established as a reliable foundation. 

(1) Thank you, Anne Lill Kvam, for pointing this out!

Canine stress-reduction, building block #1: exercise

I’m writing today’s post with a foster dog in mind. A dog that hasn’t experienced much love or trust in his life, and who’s moving into a foster home to prepare him for family life and adoption. 

Friends of mine just welcomed their second foster mix, Ema, into their homes, after their first one found his family for life. I might start working with a rescue organization myself in October – we’ll see; I’ll keep you posted. In any case, here’s the first article in a series about different building blocks a canine stress-reduction program might contain. Check back over the next weeks for other stress-reduction building blocks such as rest periods, nutrition, mental stimulation etc.

Not only people, but stressed, anxious or depressed dogs profit from exercise as well: there is a physiological reason to include long, slow and continuous workouts in canine stress reduction programs when it comes to dealing with anxiety, stress, fear or irritability. Especially long walks in quiet environments (hiking in the middle of nature …) have a positive effect, since they stimulate the release of serotonin, norepinephrine and β-endorphines. Let’s look at them more closely.

Serotonin is a neurotransmitter: a chemical substance that transmits information from one part of the nervous system to another. Serotonine influences an animal’s mood, pain perception (including the subjective pain an individual feels during emotional reactions), irritability threshold and sleep-wake cycle. In a word: a sufficient level of serotonin is crucial for mental well-being.

To give you an example: a study by Reisner et. al. found a correlation between a low irritability threshold and a lower-than-average serotonin and dopamin metabolites. Further studies showed that dogs who give a warning before biting and dogs who only bite gently have an average level of serotonin, while dogs who tend to bite without warning or harder tend to have a lower serotonin level. This is especially interesting because it shows that training your dog’s bite inhibition as a puppy is not the only factor influencing his future behavior: his brain chemistry will also have a say in his reaction. 

However, let’s take a quick look at a human example for the importance of serotonin as well. A chronic low level of serotonine causes depression. If your brain chemestry is not in balance, trying to cheer yourself up and seeing a psychotherapist might not be enough: while it will certainly be helpful, it won’t necessarily fix your serotonine levels. This is why antidepressants of the SSRI-type are designed to effect precisely the (extra-cellular) level of serotonin by means of inhibiting their re-uptake. SSRIs are frequently prescribed for depression, anxiety disorders and certain personality disorders. While the drugs won’t free you from the need to face your problems/fears/anxieties and work through them, they will help you get into a state of mind where you are able to face your fears and work through them in the first place.

Anxiety, phobias, fears etc. in dogs have been successfully treated with Prozac and similar drugs as well. The extra-cellular serotonine level is one of the places they affect. However, it should go without saying that drugs shouldn’t be the first choice when it comes to canine behavior modification. Drugs should only be used if they are necessary to help a dog (or human) to get to a place where they are able to respond to behavior modification training in the first place, but not as an “easy way out”. Furthermore, of course, drugs don’t solve the original problem, and working at learning how to cope with the environment or stressful situations in healthy ways will still be necessary. 

While I’m not a fan of always residing to chemical solutions, I firmly believe in the usefulness of conventional Western medicine for the treatment of depression or anxiety. So far, I’ve never had to medically treat these conditions in my dogs, but I have been helped by them myself. 

Norepinephrine (NE): among other things, norepinephrine (= noradrenalin) works as a neurotransmitter and hormon. It regulates your dog’s energy management. A high NE level may cause reactivity, impulsivity and irritability. A low NE level, on the other hand, causes the body to reduce its  energy use, resulting in lethargy and depression. The body can only tolerate a low NE production for a certain time before it shuts down completely: the resulting fatigue messes with the sleep-wake cycle, the ability to think rationally, it causes hyper-sensitivity to pain, and it reduces the ability to feel joy and respond to reinforcers.

Common causes for the decrease of NE production are cronic stress (shelter dogs are at risk!), traumata and learned helplessness. 

Endorphines are a dog’s natural painkiller. Furthermore, they stimulate the area in the brain where joy is experienced. Similar to humans who feel happy and relaxed after jogging (“runner’s high”), these chemical substances causes a feel-good effect in our dogs as well.

Why should a stressed or traumatized dog rather practice long, slow and continuous workouts than short and fast ones?

Short and fast, explosion-like workouts may influence the body in the same way that disstress does: it inhibits the production of NE rather than stimulating it. In extreme cases, this may even result in learned helplessness. (1) Long, slow and continuous workouts such as hikes, on the other hand, activates the NE production and increases the levels of serotonin and NE stored in the amygdala.

Does that mean agility, flyball, fetching and tugging are bad for my dog?

Of course not! Fast-paced dog sports can be A LOT of fun for both dogs and their people, as everyone who has ever participated or even only watched a dog-human team participating in them knows. As I said in the beginning, I wrote this article with a troubled dog in mind – or with a very sensitive one, if you want. And even for a dog like this, fast-paced dog sports may be a lot of fun. He may only need a little more time and gentle, understanding introduction (CU training) until he can enjoy them. 

(1) This was explored in a study with dogs on a treadmill. Cf. Steven Lindsey, Handbook of Applied Dog Behavior.

Neuropsychological foundations of CU training

CU works wonders to not only ease the life of overnoticers, overreactive or anxious dogs, it also provides a foundation for every single working or family dog out there. CU trainers stress that attention is a skill that can and should be taught separate from other tasks. Attention, focus and the ability to calm herself down are key skills that help a dog navigate her life – be it as a performance dog, a family pet or a dog adjusting to life in a big and busy city, to mention but a few.Anyone who has tried CU on their dog will agree that It works. But why does it work? Knowing about the underlying neuropsychological procedures will help you understand why CU training is so effective and enable you to design your very own tailor-made CU exercises for your dog rather than just following “recipes” developed by others. Furthermore, I hope that this article will show that CU is not just a fuzzy hit-and-miss training philosophy that will work for some dogs but not for others. Rather, it gives you and your dog a toolbox to influence your dog’s neuropsychological wiring, so to speak, in ways that make it easier for her to cope with the environment. And last but not least, it may help you to better understand your dog.
Neuropsychological implications of the threshold
CU devotees know to always work below threshold, that is to say to lower criteria to a point where we can be sure our dog will succeed, and to avoid causing over-arousal. For example, when working with a dog-reactive dog, we’ll keep our distance to other dogs. Rather than “flooding” him with the company of another dog, we’ll stay at a distance where he’s not worried. Depending on the individual, that may be the length of a soccer field, across the street, ten meters or two meters. For a dog suffering from separation anxiety, this means we wouldn’t leave her alone any longer than she’s comfortable being alone. Depending on the individual, that might mean 30 seconds, 2 minutes, 10 minutes or two hours. 
The threshold is the point where a dog overreacts – e.g. the distance where where the dog-reactive dog starts lunging, jumping into the leash and barking, or the time after which a dog suffering from separation anxiety starts getting worried and working herself up.
We can look at the threshold as the frontier separating “thinking brain” from “instinct brain”, or as the line separating cognition from emotion. Below threshold, the actions are controlled by reflection and conscious decisions. Over threshold, the emotions take over and reactions are automatic rather than deliberate. Whether an action is based on cognition or emotion depends on whether it is dominated by the cerebral cortex or an area of the limbic system called the amygdala. Both cerebral cortex and limbic system deal with environmental stimuli and work together when causing the release of hormones and neurotransmitters that generate a response. However, they are inversely proportional: the more active the cerebral cortex, the less active is the limbic system, and vice versa. Depending on which area dominates the reaction, we either get a predominantly cognitive response (limbic system is dominant) or an emotional response (amygdala is dominant). That is to say, when we work below threshold, the cerebral cortex dominates behavior and we get a deliberate response; when working over threshold, the amygdala is dominant and we get an overreactive response.
These are important points to consider in dog training. Working below threshold, a dog will be able to take in and process information, learn new things and pay attention. Because his actions are dictated by the cerebral cortex, he’s in a receptive state of mind; an ideal training condition and, moreover, a state of mind that lets your dog relax and be comfortable.
On the other hand, a dog who’s over threshold is subject to behavior triggered by the amygdala. His responses to environmental stimuli will be emotional, indeliberate and unreflected. In this state of mind, it is neurologically impossible for a dog to think clearly, to process information “objectively” and to take in new tasks. A disobedient dog over threshold isn’t stubborn; rather, his brain and hence behavior are dominated by the amygdala, while the cognitive cerebral cortex is blocked. Rather than getting mad at her for failing to listen to your cues in a distracting environment, you should ask yourself how you can change the environment/lower criteria in order to enable your dog to get back in a cerebral cortex state of mind and succeed.
Acute stress causes high activity in the amygdala. The dog’s body prepares for fight/flight/freeze/flirt, and training, attention or obedience become neurologically impossible. This is why the common practice among dog trainers to ask a dog to perform among all kinds of conditions in all kinds of situations from the beginning is counterproductive and doesn’t tend to work. Effective training starts well below threshold and only gently and slowly raises criteria. With mutual trust and practice, the threshold recedes. You may then raise criteria at the same speed the threshold withdraws, but never cross it.
2. Why targeting lets your dog stay in “thinking brain”
What do you do if your dog is reactive in a situation you can’t or don’t want to avoid? How do you get her threshold to recede without flooding (1) her with stressful experiences?
Leslie McDevitt suggests targeting in order to get your dog to focus and make it easier for him to stay in his “thinking brain” in a distracting or stressful environment. In this context, targeting means turning environmental stimuli into cues. This could be tactile targets such as getting out of the car and (A) targeting the door to the training facility, then (2) targeting the dog’s crate, and then (4) targeting her mat etc. With the help of intermediate targets, a seemingly long and distracting path is broken down into little steps that are easier for the dog (or human) to take.
The targets could also be visual, such as using scary things as a cue to play the “Look at That” game and earn treats.
Indeed, by means of targeting strategies, overreactive dogs are more likely to stay calm. Neuropsychologically speaking, why is that?
If a dog’s attention and focus are held by a well-known game, the cerebral cortex dominates his response. As mentioned above, cerebral cortex and limbic system are inversely proportional, and the activity of the limbic system is kept low when your dog operates from his “thinking brain”. Keeping the cerebral cortex going in stressful situations helps your dog to cope with them rather than going over threshold. Targeting games are a very effective way to accomplish this: the distracting environment itself provides the cues for the cerebral-cortex dominated behavior, and the more you practice, the more you accelerate calm default behavior. 
An example: Phoebe knows hand-targeting. If we’re about to cross a busy street, she sometimes gets excited and wants to chase cars: for her, the cars are a trigger causing action in the amygdala. One strategy I use for dealing with this is that I ask her to target my hand with her mouth while we’re waiting for the pedestrian light to turn green: touch my hand on the floor, in the air, next to you, behind you. Phoebe likes the touch game, and it keeps her focused on me rather than the traffic. Also, the more often I play the touch game with her in this situation, the more she’ll get used to not lunging towards the cars. While focusing on my hand, she peripherally takes in the traffic without getting emotionally glued to it, and while this experience is repeated every time we play the touch game near a busy street, she gets desensitized to the traffic trigger. Nota bene: in behavioral therapy, desensitizing only works as long as you stay below threshold!
(1) Check back soon for an article about why flooding is not an ideal way to deal with reactivity or anxiety in dogs.