Triggers and Underlying Causes of Dog Aggression: Part 1: Tight Leashes

"The hallmark of good dog training is a slack leash." - classic dog training mantra, source unknown.


A tight leash is by far the most common and overlooked underlying problem with dog aggression. I rarely, if ever, see a case of aggression in which the owners have consistently been maintaining a loose leash. In fact, about the only time a tight leash is not a factor in aggression cases is when dealing with dogs that are never on a leash. In such a case, however, we usually have to introduce leash training in order to help with the aggression, so it still comes back to effective leash training. 


Effective leash training means consistently maintaining a loose leash…anytime and everytime the leash is on...when you're standing still…when you’re walking…when the dog is focused on you…when the dog is not focused on you…when you have treats…when you don’t have treats…you know, consistently, all the time, did I say that already?  


Please note, this is not a "how to" article on leash training, it is a "why to" article on how damaging a tight leash is and how it is connected to aggression as well as a whole bunch of other behavioral and psychological problems. The technique or type of collar you choose can become a heated, controversial debate, but I am not interested in drama, I simply want to discuss why a loose leash is so important. Fair enough? Ok, here we go: 


Defining a Loose Leash 

  • A loose (slack) leash has a visible dip in it. 
  • A truly slack leash can be held in an open palm. See video below:

Note: In the video I am walking four dogs but it's best to start with one dog at a time and add them together after they are trained individually. 



  • Dog pulling on leash
  • Human pulling, dragging or restraining the dog with a leash 
  • Dog pulling while on a tie out (tether)
  • All of these are problematic uses of a leash. Keep reading to understand why.

Tension in the leash can be both a trigger for aggressive behavior and an underlying factor that leads to aggressive behavior at other, seemingly unconnected, times...even when off-leash. 

  • Tension in the leash has a negative effect on the dog’s psychological and emotional state. 
  • It primes the dog to be more reactive or aggressive when something worthy comes along.
  • This “primed” state may be associated (classically conditioned) with all sorts of situations. 
  • Tension in the leash is connected to a majority of the other factors affecting aggression, which will be discussed in the rest of the series. (see: Hyperactivity, Overly-Intense Play, Rude Behavior, Dominance, Frustration, Fear, Stress, Pain) 

Tension - Frustration - Aggression 

  • Tension in the leash puts tension in the dog. 
  • Tension creates frustration. 
  • Frustration leads to rage or aggression.
  • Aggression is an easy and natural way  for dogs to release frustration. 
  • Frustration is a form of stress and stress is a form of mental/emotional pain. (see: Pain, Stress)

Lack of Impulse Control 

  • Dogs pulling or being restrained are not developing any form of impulse control or self restraint. They may be physically held back but psychologically and emotionally they are going bonkers. 

Frustration Intolerance

  • Dogs pulling or being restrained are not developing any form of frustration tolerance, they are being allowed to vent their frustration by pulling, which only creates more frustration. Did someone order a vicious cycle?

Builds Drive (good or bad)

  • Restraint is intentionally used in dog training to build “drive” in protection sports as well as for building a strong recall. 
  • In pet dogs, it is commonly used accidentally and intensifies the dog’s desire for anything and everything of interest other than you. 

Intensifies “Opposition Reflex” 

  • Dogs have a natural instinct to fight against physical pressure which is called “opposition reflex.” 
  • Allowing the dog to pull only intensifies this natural reflex, which then leads to the downward spiral of negative responses connected to aggression.     

Intensifies Flight or Fight Response (Defense Drive)

  • Dogs can feel trapped when restrained by a leash which can trigger the flight or fight response, which can obviously lead to aggression. (see: Fear, Pain, Frustration)

Opposite of Engagement: 

  • Drives dog’s attention away from you. 
  • The dog is literally trying to get away from you with every step. 

Opposite of Bonding: 

  • Dog is physically and mentally trying to escape from you.

Opposite of Leadership: 

  • If the dog is pulling and you move forward, you are literally and figuratively following the dog. If you move forward when the dog pulls, you are the one who is yielding to the leash. If yielding = submitting, then by following a pulling dog, you are submitting. If you are following and submitting, by default the dog is leading and dominating. The dog may not interpret their behavior as dominance but you are definitely not leading, at best you are just a hindrance to the dog’s forward momentum. No one wants to partner with someone who “holds them back.” 
  • If dogs can drag people around, how can they be expected to see those people as being in control or having any authority over them? (see: Dominance

Solution = Balanced Basic Obedience Training

  • If you can’t stop the dog from pulling on the leash in normal conditions, how can you expect to stop the dog from being aggressive? 
  • Dogs that pull on leash are also less likely to obey other commands such as come, stay or leave it. 
  • If you are in the California Bay Area, you can sign up for our classes here: Class Sign Ups
  • If you are out of the area, you can purchase the online course here: Basic Obedience Course

Learning how to use the leash correctly, and doing so consistently, will eliminate 50% of dog aggression problems without even getting into the details of the aggression. No, I’m not even joking, it’s that big of an issue. Hence, developing this skill should be step number one, then we can take a deeper dive into other factors pertaining to aggression.  


Chad Culp, Certified Dog Trainer, Canine Behavior Consultant, Owner of Thriving Canine. 

© Thriving Canine 2022

Please use the links below to follow the whole series for a more complete understanding of the triggers and underlying factors of dog aggression.

Related Topics:

Triggers and Underlying Causes of Dog Aggression: Part 1: Tight Leashes

Triggers and Underlying Causes of Dog Aggression: Part 2: Hyperactivity and Anxiety 

Triggers and Underlying Causes of Dog Aggression: Part 3: Overly Intense Play

Triggers and Underlying Causes of Dog Aggression: Part 4: Fear and Anxiety

Triggers and Underlying Causes of Dog Aggression: Part 5: Frustration and Agitation

Triggers and Underlying Causes of Dog Aggression: Part 6: Obnoxious Submission

Triggers and Underlying Causes of Dog Aggression: Part 7: Dominance


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