Trigger stacking is the process of experiencing lots of triggers in a short space of time sending your dog into a melt down.

If your dog doesn’t have the opportunity to calm down after a scary experience, stress levels will continue to rise. Once a dog has reached his coping threshold he will most likely react to all triggers when at other times he seems ‘fine’. If a dog reaches his threshold it can take as long as 72 hours to calm down.

Consider a cup filled with water. Every time a scary experience happens, water is poured into the cup. If we don’t empty the cup each time, water will eventually spill over causing a mess.

When a dog isn’t able to cope with certain triggers in the environment but we are able to manage the situation by increasing distance and creating a safe space we can help the dog to remain under their coping threshold.

Here’s a couple of examples of what can happen:
A dog who is frightened of traffic may be ‘fine’ with the first three vehicles passing by but then reacts to the 4th vehicle. There may not be anything different about the vehicles but four triggers is all your dog can take in a short space of time.


You are walking to the park, the dustbin men are collecting the bins, a child has just fallen off his bike and is screaming, a runner has gone whizzing by and someone has slammed a car door shut. Your dog seems absolutely fine with this but when you get inside the park your dog sees a dog walking on lead with his owner and starts lunging and barking which is unusual!

Trigger stacking is often a reason why dogs bite ‘out of the blue’. He may be able to cope with certain things on some days but when we start stacking them up in a short space of time it is a recipe for a reaction.

So when we feel confused as to why our dogs react to random things this may not be the case at all – the signs are there, if we look carefully and consider how much our dogs can actually cope with.

So bear this in mind – if your dog does react, what ACTUALLY happened to make the dog behave in this way? Is it really random? If you do notice lots of triggers in a short space of time, help your dog by creating distance and allow your dog to recover at home in his safe space.

If you are struggling with your dog please get in touch by emailing