Everything is fine. You’re walking your usual route, the leash is still fairly loose, and you’re almost starting to believe that today might be different. Then a dog appears at the end of the street.

In a split second, everything changes.

Your dog freezes, locks their gaze straight ahead, their body tenses, and the leash tightens. A moment later, they’re barking, pulling, jumping, lunging. You call them, plead with them, correct them, maybe try asking for a “sit,” maybe hold a treat in front of their nose. But it’s as if you’re no longer there. As if the dog who knows everything at home suddenly loses access to their entire brain on a walk.

Situations just like these were the starting point of a webinar on reactivity in dogs, led by Alja Willenpart, a canine behaviour consultant from the dog school psuprijazen.si. This article summarizes and builds on the key points from her talk: what happens inside a dog when they “explode,” why commands often fail in those moments, and why reactivity cannot be understood simply as a training issue.

One of the strongest ideas Alja emphasized right at the beginning is also the thread running through this article: a reactive dog isn’t giving you a hard time. A reactive dog is having a hard time.

That is a big difference.

They’re not being disobedient. Their nervous system is overwhelmed.

When a dog barks, pulls, lunges, or “goes crazy,” it is not necessarily a sign of poor training. As Alja Willenpart explains, reactive behaviour is always driven by a strong emotion, most often fear or frustration.

From the outside, it can look similar: the dog sees another dog and starts barking. But underneath, two completely different stories may be playing out.

Put very simply, the behaviour may be driven mainly by:

• fear , when the dog is saying through barking and lunging: “Go away. I don’t feel safe.”
• frustration , when the dog is really saying: “I want to get there, but I can’t.”

If fear is involved, the dog is often trying to create distance through the reaction.

If frustration is involved, the dog may actually want contact, play, or to move closer, but the leash, the distance, or the situation prevents them. The frustration builds until it bursts out.

As the expert explains, this is why it is so important to understand what is behind the behaviour. Because we do not teach a fearful dog in the same way we teach a frustrated dog. And we help neither of them by forcing them into situations they cannot cope with.

Why do commands fail exactly when you need them most?

One of the biggest frustrations for guardians is this: the dog knows it at home. Sit. Wait. Come. Look. But on a walk, nothing.

This is not because they are ignoring you. As Alja explained in the webinar, when a dog is under intense stress, the fight-or-flight response is triggered in the body. The body prepares for survival, not for a neat obedience exercise.

In this state, several things happen at once:

• adrenaline rises,
• heart rate and breathing speed up,
• energy is redirected to the muscles,
• reactions become faster and more impulsive,
• rational thinking and learning become much harder.

That is why a cue that works perfectly in the living room fails when the dog encounters a trigger. The dog finds it harder to think, harder to learn, and harder to hear what you are saying. Their system is in “save yourself” mode, not “work with me” mode.

This is not the moment to prove authority. It is the moment when the dog needs more distance, more safety, and less pressure.

Reactivity does not start with barking. It starts much earlier.

Many guardians only notice the problem once the dog is already barking. But by then, the reaction is often already in full swing.

As the canine behaviour consultant points out, the reaction builds earlier. Long before the barking starts, the dog often shows that their “stress cup” is filling up.

The first signs can be very subtle:

• the dog stares at the trigger,
• the body tenses or stiffens,
• the mouth closes,
• the walk changes,
• the leash begins to tighten,
• the dog stops sniffing,
• they find it harder to respond to your voice or to a treat,
• they seem “locked on” to what is happening ahead.

In the webinar, Alja uses the very clear metaphor of a cup. If a dog starts the day with their stress cup already almost full, one dog, one cyclist, or one unfamiliar sound may be enough to make the cup overflow. But if the dog has had more rest, less pressure, and a greater sense of safety, their tolerance threshold is higher.

That is why, with reactive dogs, what we do in the moment of the reaction is not the only thing that matters. The dog’s entire day matters too.

To hear the full explanation, real-life examples, and a more detailed breakdown of when a dog can still cooperate and when stress has already overwhelmed them, watch the recording of the webinar with Alja Willenpart.

Why recovering from stress is not “rest for lazy dogs”

With reactive dogs, we often do the exact opposite of what would help them. We add more training, longer walks, more exercises, more redirection, more commands. Because we feel we have to “do something.”

But as Alja emphasizes, in many cases these dogs already have too much going on. Too many stimuli, walks that are too long, too much activity, and not enough real rest.

For sensitive dogs, the “stress cup” can also be filled by things guardians often do not connect with reactivity:

• walks that are too long or too intense,
• constant exposure to triggers,
• too little quality sleep,
• pain or physical discomfort,
• digestive issues,
• too many obedience exercises,
• throwing balls, sticks, or frisbees,
• too few opportunities to sniff, explore, and calm down.

Even throwing balls and sticks, which may seem like harmless fun, can further increase arousal and impulsivity in sensitive dogs.

A dog under chronic stress finds it harder to learn, sleeps worse, and struggles more to calm down, because their body does not have time to return to balance.

That is why the first step is sometimes less: fewer triggers, shorter walks, more sniffing, more predictability, more safety. Only once the nervous system has settled a little can the dog begin to take in new information.

What do digestion, the gut, and stool have to do with behaviour?

One of the most interesting parts of the webinar is the link between behaviour, stress, and the dog’s physical state. According to Alja Willenpart, reactivity cannot be viewed separately from a dog’s health, wellbeing, and diet.

Stress affects digestion. After a highly stressful event, stool may become softer or the dog may get diarrhoea. With chronic stress, digestive problems, poorer recovery, increased sensitivity, and a vicious cycle can develop, making it harder and harder for the dog to cope with new stimuli.

That is why, with dogs who become aroused quickly, are sensitive, stressed, or also have stool issues, it makes sense to look at the bigger picture:

• how the dog sleeps,
• whether they get enough peace,
• whether something hurts,
• what their diet is like,
• what their stool is like,
• how many stimuli they experience every day,
• whether they have enough safe, calm experiences,
• whether behavioural work is happening at a distance where the dog can still cooperate.

The gut is not just a “digestive tube.” It is an important part of the dog’s internal balance. And if that part is not working optimally, it can also show up in the dog’s overall wellbeing, stress resilience, and day-to-day stability.

We do not “fix” a reactive dog. We help them cope.

The most honest conclusion from the webinar is this: reactivity is not one problem with one quick trick. We do not fix a reactive dog by adding more commands. We help them by understanding what overwhelms them, where their tolerance threshold is, and what they need for their body to even begin to calm down.

That means professional behavioural support, appropriate training, enough recovery, safe experiences, and often physical support as well.

This is where Pawital Belly Biotics and Cozy Calm can naturally fit in. Not as a replacement for behavioural work, training, or veterinary advice, but as part of a broader, holistic routine.

Belly Biotics are daily probiotic treats for dogs, designed to support the gut, digestion, and internal balance. They contain prebiotics, probiotics, and postbiotics, with each serving providing 1 billion proven live bacteria. They make particular sense for dogs whose stress also shows up in their digestion, stool, or overall wellbeing.

Cozy Calm is designed to support calmness in dogs who struggle to process everyday stimuli, become aroused quickly, or are more sensitive to stress. It does not eliminate reactivity and does not replace work with a behaviour professional, but it can support the dog as part of a thoughtful daily routine.

For the guardian of a reactive dog, the key points are:

• the dog does not need more pressure, but more understanding,
• the reaction is not the start of the problem, but its outburst,
• training only works once the dog is calm enough to learn,
• rest, gut balance, routine, and behavioural support are all part of the same story,
• the goal is not a “perfect dog,” but a dog who feels safer in the world.

That is why, with a reactive dog, it makes sense to think beyond training alone. Behavioural work remains the foundation, but a dog can make progress more easily when they have a routine that also supports their body: calmer days, enough rest, fewer unnecessary triggers, and healthy digestion and internal balance. This is where Belly Biotics and Cozy Calm can become a practical part of everyday support: the first for the gut, digestion, and microbiota, the second to support calmness in dogs who are easily overwhelmed by everyday stimuli. Not as a quick fix for reactivity, but as a thoughtful addition to a holistic approach that helps the dog cope better with the world around them.