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Barrier Frustration Introduction


This protocol can be used to evaluate if barrier-frustrated dogs are comfortable interacting with other dogs when the barrier frustration is removed. Dogs who become easily frustrated and are known to enjoy playing with other dogs off-leash can  be brought into an ongoing playgroup using the off-leash dog introduction protocol or the on-leash dog introduction protocol. Because a leash is a type of "barrier", off-leash introductions might be more successful for these dogs. 

“Barrier-frustrated” dogs react to other dogs by barking, lunging, growling, and/or snarling when on-leash or behind a barrier like a gate, fence, or window. 

Barrier-frustrated dogs often play well with other dogs off-leash. This behavior occurs frequently in many shelters where dogs have limited access to other dogs.

It’s impossible to tell by in-kennel or on-leash behavior whether a barrier-frustrated dog will be friendly or aggressive if introduced to other dogs without a barrier between them.  Understandably, many shelters play it safe and house reactive dogs singly, and keep them away from other dogs. Unfortunately, isolating a barrier-frustrated dog from other dogs only serves to increase frustration and could be harmful to the dog’s welfare.


Fight kit, fully enclosed play area, leashes, high-value treats.


1. If possible, select a potential playmate who is:

  • Dog-social

  • Adjusts his play style to his playmate

  • Is tolerant of dogs charging up to him & jumping on him

  • Doesn't tend to fight back (escalate) if another dog aggresses.

2. Handlers doing the introduction should communicate about when the dogs should be brought together or released to meet. Fumbling with clips or otherwise delaying the dogs’ meeting once they have become aware of each other can result in increasing frustration.

3. Before arriving in the yard:

  • Block line of sight between reactive dogs & other dogs using visual barriers like vegetation or screens/tarps on fences.

  • If possible, avoid walking barrier-frustrated dogs past other dog kennels on the way to the play yard.

4. On-leash Introduction methods. These are best used in smaller areas to avoid dogs pulling toward each other from a distance, creating tight leashes. Any leash tension at all can cause a barrier-frustrated dog to lunge and bark. 

  • On-leash, quick method: This is the Standard On-Leash Dog Introduction. You might prefer this method if your shelter is less risk averse and/or if you have reason to believe the barrier-frustrated dog is dog-friendly.

  • ​Let the dogs meet as quickly as possible. You might have to run to assure that the leashes are loose when the dogs meet.

  • Maintain loose leashes throughout the introduction.

  • To prevent leashes from tangling and allow for quick separation of the dogs, both handlers should move around the dogs to maintain positions on opposite sides of the dogs (180 degrees apart.)

  • If leashes tangle during an introduction, handlers should coordinate to untangle them as quickly as possible.

  • On-leash method using treats:

  • Start with the helper dog facing away from the barrier-frustrated dog. Use treats, happy talk and/or favorite toys to distract their attention from the frustrated dog. Head-to-head on-leash greetings are often unsuccessful with barrier-frustrated dogs.

  • To keep the reactive dog from pulling toward the helper dog, distract him with very high-value food like warmed-up meatballs. While walking, toss the high value treats on the ground in front of the dog so he slows down to eat them. You might need to place the treat right in front of the dog’s nose so that he notices it, then drop it in front of him. This will often slow down the dog’s approach.

  • If the dog does not eat the meatballs, make sure to pick them up off the ground before releasing the dogs to play.

  • The handler distracting the helper dog should distract him by dropping treats onto the ground while the other dog approaches if possible. Avoid hand feeding. If the reactive dog jumps on or bites the helper dog, there is a risk of a redirected bite if there is a hand close to the helper dog’s mouth. 

  • When the barrier-frustrated dog is less than about 6’ from the helper dog, allow the frustrated dog to sniff the helper dog’s rear if it is possible to keep the helper dog distracted with treats. Do not let the barrier-frustrated dog approach any treats still on the ground. 

  • If the helper dog cannot be distracted, a face-to-face meeting can be attempted with loose leashes.

  • Keep moving around the dogs so the leashes do not get taut or tangled.

  • If both dogs show playful body language, drop both dogs’ leashes.  (See Monitoring Leashes)

5. Off-leash introduction methods (leashes left on and dragging is recommended). Depending on your shelter’s policies and how risk-averse the handlers are, you can start with off leash introductions or proceed to this after doing an on-leash introduction.

  • Have the helper dog in the play area first and distract them with treats or toys while the frustrated dog enters and has their leash dropped. 

6. Monitor the interaction closely (see When to Intervene), intervene as needed:

  • If either dog behaves aggressively or shows tense, anxious or fearful body language, use a positive interrupter, call away, or gently restrain one or both dogs (see How to Intervene). Give both dogs treats when separated.

What if the introduction goes badly? You might decide to try the introduction again if:

  • You’re unsure that the protocol was followed (e.g. leashes might have been tight);

  • The aggression/fear was very mild, and is improving or not worsening if you have already tried multiple introductions with this pair;

  • One or both of the dogs in question don’t have other playmates and this might be the most compatible pairing available;

  • You need to determine whether one or both of the dogs are dog-friendly, and you feel this is the best pairing available. 

After the initial introduction, and after monitoring play, record what you learned about the dog in the Dog Play Profile Sheet, as well as any interactions between particular dogs in your Playgroup Notes summary. Record specifics of what may have caused frustration (e.g. tension on leash, dogs saw each other through fence, etc.)


It can be immensely helpful to teach some dogs a few behaviors before introductions (coming soon: Behavior Modification for Leash Reactive Dogs)

  • “Watch me” - Teaching a dog to offer eye contact to a handler on cue can help a dog walk more politely on leash (instead of pulling ahead). This behavior can often even replace barking and lunging.

  • “Let’s go” - Teaching a dog to switch directions and walk the opposite way when walking on leash can help a handler get out of a tense or sticky situation.

  • Recall (coming when called) - Teaching a dog to reliably run to a person when he hears a particular cue (a word, squeaker, whistle, etc.) can help in the event of a scuffle or tense situation between dogs.

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