Why Does My Dog Bite When People Leave?

Whether your dog is biting out of fear or instinct, long-term management, behavior modification, and behavioral assessment can all help.

Why Does My Dog Bite When People Leave?
Long-term management, behavior modification, and behavioral assessment can all help curb biting in dogs.


Help, My Red Heeler Bites When People Leave

"We have a 4-year-old, rescued, deaf red heeler. He has been with us for 3 years now. We've never had a heeler and have learned that they are very different. Although loyal and loving, we have to put him in his kennel when someone leaves because he will bite them if he's loose. He doesn't have any issues letting guests enter the house, though.

He was very badly abused as a puppy. We don't have cattle so he can fulfill his "job." He has been through training, and I don't think any rescue would take him due to his aggressions. Do you have any ideas? Thank you." —Kathy

Your Guests' Safety Is Your Priority

If your dog is biting when someone leaves, it’s important to make the safety of your guests your top priority. This can be a critical situation, especially if your dog’s bites are damaging (tooth punctures, etc.), but I see you are already taking steps to prevent bites by kennelling him.

Let’s start by taking a closer look at this behavior, what its possible function is, and what options are available to address it.

Why Is Your Dog Biting Guests When They Leave?

When behaviors put down roots and become established, there is usually some type of reinforcement going on. In this case, it is possible that your dog’s behavior is maintained by the fact that guests leave contingent upon his threatening behavior.

The Behavior Is Being Reinforced

This is likely to take place when a dog perceives the presence of visitors as an aversive social interaction, and the reaction is usually fear-based. When people leave (either by chance because it was time to leave or as a direct reaction to the dog’s behavior), this reinforces the behavior, allowing it to repeat in future interactions.

The Behavior Is Innate

There may also be some instinctive, non-fear-based, breed-specific elements at play here where chasing and attempting to bite the leaving visitors is internally reinforcing due to the deeply ingrained herding traits in these dogs (more on this at the end of the article).

Option 1: Long-Term Management

When it comes to instances where dogs bite and threaten to bite, safety is always paramount. If you only have visitors occasionally, you may wish to continue what you are doing by placing your dog in the kennel to prevent the behavior.

This can be a long-term management goal as long as it’s instituted very carefully and consistently with all family members on board (in other words, this needs to happen every single time guests leave your house).

Pros of Management as a Long-Term Solution

Managing the behavior as a long-term solution provides several advantages.

  • It Prevents Rehearsal of the Problematic Behavior. The more your red heeler rehearses the threatening-to-bite behavior, the more it establishes the behavior considering its reinforcement history.
  • It Helps Keep Your Guests Safe. As already mentioned, the safety of your guests is paramount. When stringent management protocols are in place 100 percent of the time, it can help prevent incidents.
  • It’s Labor and Cost Effective. When management is instituted as a long-term solution, it is cost-effective (no need to hire professionals) and energy efficient (no need to spend time and effort on training and implementing behavior modification).

Cons of Long-Term Management

  • It's Difficult to Implement Consistently. It can be hard to manage your dog's behavior all the time for the rest of the dog’s life and with all family members and visiting guests 100 percent on board. There are always chances for mishaps (the kennel door is not locked well, a guest happens to unexpectedly rush out of the door, children not following directions, etc.).
  • It Isn't Foolproof. You will need some secondary or even tertiary back-up plans to cover up for such mishaps, such as acclimating your heeler to wear a bite-proof basket muzzle when guests are over, keeping him on a leash, or closing the door of the room where he is kenneled.

As a general rule, if management remains the only way to prevent your dog from potentially harming a visitor, then the situation can be quite critical. It would therefore be ideal to tackle the root problem along with implementing management, which brings us to the second option.

Positive reinforcement (such as giving treats for good behavior) is much more effective than punishment-based methods.


Option 2: Behavior Modification

The goal of behavior modification is to address the root of the problem while management options are also in place as the dog learns to better cope with the situation.

Work With an Accredited Professional

Considering the risk of being bitten, behavior modification will need to be carried out under the guidance of a behavior professional. Please be careful—anybody can easily call themselves dog “behaviorists” nowadays. It is very important to check credentials and referrals.

My favorite go-to professionals are Board-certified Veterinary Behaviorists (DACVB) and Certified Applied Animal Behaviorists (CAAB), but these are not always easy to locate. A credentialed dog trainer specializing in tackling aggression is another option, but you’ll need to ensure they are committed to positive, dog-friendly training and behavior modification techniques.

Use Only Non-Confrontational Techniques

The American Veterinary Society of Animal Behavior (AVSAB) emphasizes the importance of having veterinarians refer clients only to trainers or behavior consultants who adhere to non-confrontational techniques, using scientifically based guidelines of positive reinforcement, operant conditioning, classical conditioning, desensitization, and counterconditioning.

The use of the above AVSAB recommended methods for behavior modification may vary on an individual basis depending on several factors. Below are several examples of behavior modification techniques.

Desensitization and Counterconditioning

  • Desensitization: Desensitization entails exposing the dog to a trigger or situation at a low-intensity level that doesn’t evoke the problem behavior. Care must be taken in not causing the dog to go “over threshold.”
  • Counterconditioning: Counterconditioning entails creating positive associations (often through the use of high-value treats like baked liver/chicken) with the goal of altering the dog’s emotional response so as to no longer feel motivated to chase/bite visitors.

Counterconditioning and desensitization are often combined, allowing for a synergistic effect.

As a general example, your behavior professional may suggest putting your dog on leash at a distance from a guest, and the guest may be instructed to pretend he is about to get up and leave, but without carrying out the whole leaving sequence (which is known to evoke the wanting to bite behavior).

The guest may therefore be instructed to just put his hand over the armrest as if about to get up from the couch, but without getting up. As the dog watches this action, he is fed a tasty treat.

Once the dog shows signs of coping well with this, the difficulty can be increased (the next step is taken), and the guest may be instructed to stand up (without going anywhere). As your dog watches this, he is fed a treat.

Next, the guest may walk one step, and the dog is fed treats. Afterward, the guest may walk two steps, and the dog is fed treats. This process continues until the guest is able to walk out of the door as your dog is fed several treats in a row (treats can also be tossed around for a fun chase-the-treat game). Guests may also be instructed to toss the treats themselves as they exit.

If at any point there are setbacks (the undesired behavior returns), the professional will carefully evaluate the circumstances and suggest working at a lower level of intensity before proceeding to the next step.

The ultimate goal here is to change your dog’s emotional response towards guests leaving while also giving him something to do (looking/searching for treats). This can be effective in the case he feels the presence of guests to be somewhat aversive.

Teaching your dog a "go to mat" or "park it" cue can be extremely helpful!


Response Substitution

In some cases, such as when it’s not clear whether the dog perceives a certain stimulus or situation as aversive or when behaviors are occurring due to instincts, it may help to directly approach the issue through operant conditioning (the basis of dog training).

Response substitution entails engaging the dog in an activity that substitutes the problem behavior. In other words, its essence can be depicted as “what would you like your dog to do rather than chase/threaten to bite visitors?”

Often, this entails adopting behaviors that are incompatible with the problem behavior. In other words, a dog cannot chase guests if he’s asked to lie on a mat and is rewarded for that with something extra valuable. Of course, this involves training a "go to mat" behavior (using a hand gesture rather than a verbal cue since he’s deaf) at a very fluent, proficient level using high-value reinforcers (treats).

Backup safety protocols and management will need to be instituted during any behavior change process, and several may still need to be kept in place depending on the results attained.

Ensuring that your dog is adequately exercised is key to reducing problem behaviors (especially for high-energy breeds like cattle dogs).


A Multi-Model Approach

On top of behavior modification, it is important to take other steps to help ameliorate the situation. Following are several general potential guidelines.

  • Rule Out Medical Problems. Sometimes medical conditions can contribute to behavior issues and may lower a dog’s threshold for aggression.
  • Provide Your Heeler With Exercise and Mental Enrichment. As herding dogs, heelers may easily get bored, and this can sometimes contribute to the onset of behavior problems and neurotic behaviors. Many energetic heelers enjoy herding large balls (as in the dog sport of Treibball), which can be purchased online. Food puzzles and brain games are another great way to keep them mentally stimulated.
  • Stick to a Routine. Many fearful, insecure and stressed dogs benefit from structured routines in their daily lives.
  • Become a Pro at “Reading” Your Dog. This will allow you to quickly identify the earliest signs of stress/fear that are precursors to potential biting.
  • Avoid Punishment-Based Methods. Studies have reported that many aversive, punishment-based methods (such as yelling, alpha rolling, removing objects out of the dog’s mouth, etc.) exacerbate aggression.
  • Reduce Any Stress/Anxiety in Your Dog’s Life. There are many calming aids for dogs such as DAP collars and diffusers, calming supplements etc. Consult with your vet on whether your dog may benefit from these.

Option 3: Get a Behavior Assessment

If you are not sure whether you want to pursue the behavior modification route, or other family members do not agree, it may still be valuable to consult with a behavior professional and at least carry out an assessment.

By assessing your dog, a reputable behavior professional can determine if there are any behavior modification programs and/or prescription drugs that can help your dog. He or she may also provide insights into determining his general prognosis.

It Never Hurts to Ask About Rehoming

While rescue groups and shelters won't typically take aggressive dogs (since their goal is to ultimately safely rehome the dog), they may know volunteers or other people that may take a dog if his/her level of aggression has been deemed to be not significantly dangerous by a behaviorist. It never hurts to inquire.

Australian cattle dogs require intensive training from an early age.


A Word About Heelers

As you may already know, Australian cattle dogs, also known as heelers, were selectively bred to herd cattle. This is how the term “heeler” was coined. As herders, they are very attracted to movement, and they are prone to wanting to nip the feet and legs of people or animals.

This breed’s modus operandi was to bite stubborn cows’ heels to get them to move. Biting in Australian cattle dogs is therefore a deeply ingrained behavior that we see with a certain intensity as early as puppyhood, with many owners complaining about excessive nipping in their heeler pups. With proper guidance, this behavior should ideally disappear once they reach adulthood.

The official standard for the breed also mentions that these dogs are naturally suspicious of strangers, and their protective instincts make them valuable assets for guarding herds and properties.


  • American Kennel Club: Official Standard of the American Cattle Dog
  • Radosta, Lisa & Shofer, Frances & Reisner, Ilana. (2007). Comparison of 42 cases of canine fear-related aggression with structured clinician initiated follow-up and 25 cases with unstructured client initiated follow-up. Applied Animal Behaviour Science - Appl Anim Behav Sci 105.
  • University of Pennsylvania. "If You're Aggressive, Your Dog Will Be Too, Says Veterinary Study." ScienceDaily. ScienceDaily, 18 February 2009.
  • Meet Your Dog: The Game-Changing Guide to Understanding Your Dog's Behavior, Kim Brophey, Chronicle Books, 2018

If your puppy or dog shows signs of potential aggression (lunging, barking, growling, snapping, biting), please consult with a dog behavior professional for direct in-person guidance. Articles, videos, and general information provided online are not meant to replace in-person training/instruction. By using this service, you are waiving any liability claims or other types of claims related to any of your dogs' behaviors against you or others.

© 2023 Adrienne Farricelli CPDT-KA, Dip.CBST

(Excluding for the Headline, this article ("story") has not been edited by MiBiz News and is published from a web feed or sourced from the Internet.)