Aggressive tri-coloredJack Russell Terrier on a leash barking.

Are Rescue Dogs More Aggressive? Things You Should Know

Last updated on June 10th, 2024 at 07:35 pm

If you have ever gone to a shelter or rescue facility, chances are you heard a lot of barking. Your apprehension level may have sky rocketed as you entered in hopes of finding a nice doggie to take home. But with all of these barking dogs how could you possibly find a well mannered pooch as your new best friend?

Rest assured that just about any dog who has been in a shelter for a while will probably bark when a visitor approaches. Shelters are noisy, strange places, not very homelike, and often stressful. As a result, most dogs will act out by vocalizing or exhibiting other behaviors of stress.

Rescue dogs, however, are not, by nature, more aggressive than any other dog. Instead, shelter dogs often display reactive behavior due to anxiety, fearfulness, or stress due to being confined. In addition, they have been displaced and have yet to learn what is next and who to trust.

The true personality of dogs in rescue facilities is often masked by the strategies they have adapted to cope. So just know you actually have a good chance of finding that loyal, loving dog you have always wanted at a shelter. But there are some things you should know.

Why Dogs Are Rescued and End Up In Shelters

People sometimes assume that dogs are placed in shelters due to bad behavior. Yet, behavior is one of the less common reasons that dogs end up in shelters and rescue facilities. The more frequent reasons dogs are in shelters are because of a significant change in their owner’s life or because they have been rescued from an abusive situation. Please see my post-Rescue Dogs Are Not Broken! for more information.

Additionally and sadly, some dogs are given up for adoption due to a health problem or their age. Some owners do not have the resources, ability, or desire to deal with an aging dog especially when illness becomes an issue. Luckily many rescue facilities provide a safe haven for senior dogs. Senior dog facilities like Lily’s Legacy in Northern California have a high success rate of rehabilitating and rehoming older dogs who need a second chance. You can see more about adopting senior dogs here.

Scientific Studies and Observations About Shelter Dog Aggression

A study done in Austria of dogs in four different shelters evaluated the behavior of short term and long term shelter dogs. All four shelters were “no kill” shelters due to Austrian law. Short term stays were defined as 5 months or less and long term stays were considered to be a year or more. The researchers evaluated a total of 1,560 dogs which included 1,299 short-term dogs and 141 long-term dogs.

Staff at the shelters indicated that some of the long-term dogs had been surrenderd to their shelter due to behaviorial issues such as aggression.However, this was a minor factor. It is also important to note that only 9% of this large group of dogs ended up staying for more than a year.

Shelter dogs jumping and reacting toward a visitor.
Shelter dogs jumping and reacting to a visitor.

The researchers noted that the longer dogs stayed at shelters the more stressed and reactive they became. Due to the isolation and unnatural living conditions, long-term dogs had higher arousal and aggressive behavior toward unfamilar people and sometimes other animals.

But the researchers could not conclude that these long-term shelter dogs were genetically more aggressive than any other dog. Instead, they proposed that they were reacting to their environment or past treatment before being in the shelter.

Therefore, they recommended creating a more hospitable environment for dogs at risk of not getting adopted for long periods. Dogs in this category were often older, intact males or considered to be a “fighting breed.” Pit Bulls, for example, are often labeled as vicious dogs when it is actually bad owners who abuse these sweet dogs.

Additionally, the researchers made ethical recommendations to provide rehabilitation for dogs from abusive situations upon arrival. They believed early intervention would prevent highly aroused, fearful dogs from becoming more fearful and aggressive, leading to poor adoptability and longer stays.

Why a Dog (Any Dog) May Become Aggressive

Most rescue dog workers and trainers do not experience shelter dogs as being naturally aggressive over other dogs. With the exception of a small percentage of dogs who may be genetically more pre-disposed toward reactive or hostile behavior, other factors come into play. Early socialization, sufficient exercise, daily interaction with family members and other pets, and loving treatment make a huge difference in a dog’s disposition.

Lois Harford answered a Quora question: Are Rescue Dogs More Aggressive? “No. Rescue dogs are individuals, just like any other dogs. Their personalities and temperaments are going to depend in part on their genetic makeup, how they were raised, and what their experiences were before they became “rescued”. Many rescues are total lovebugs, some are reserved because they have difficulty with trusting humans, and some may have behavior problems ranging from just being untrained to being anxious to being destructive. In most cases, dogs that are known to be aggressive will not be adopted out.”

Terrified small stray dog hiding under a shelf
Terrified small stray dog hiding under a shelf

Other factors that may cause a dog to become aggressive include:

  • Injury, sickness, or pain
  • Extreme fear
  • Hunger
  • Recent abuse or neglect
  • Isolation and lack of socialization

The good news is that dogs are very resilient. Positive experiences will eventually replace past heartaches and challenges. Dogs can be rehabilitated, healed, and taught to trust, and love when given the opportunity. In many countries, shelters and rescue groups do their best to rehab and care for their wards prior to placing them up for adoption.

Signs of Aggression

Small dog baring teeth and growling at owner
Don’t touch me! Small dog baring teeth and growling at owner.

Symptoms of extreme stress and fear can often be subtle prior to turning into aggressive behavior:

  • Baring teeth
  • Chewing on feet or bedding
  • Licking themselves or their surroundings constantly
  • Sleeping with their heads up
  • Pacing
  • Circling
  • Vocalizing continually — growling, whimpering, whining, barking
  • Panting
  • Staring intensely
  • Hiding or running into the corner of the room when approached

These symptoms could predict aggressive behavior if a dog is provoked. But again, it is important to note that these behaviors are often a reaction to extreme fear and stress rather than due to a hostile personality.

How to Manage Aggressive Behavior

Dogs with owners in obedience class learning to get along with each other.
Obedience class–dogs learning to socialize and get along with each other.

If Your Rescue Dog is Aggressive Be Patient and Give Him Plenty of Space

Fortunately, most rescue groups do a lot to help a dog transition to his new home. The shelter or facility can be a great resource to help you manage any behavioral problems after adoption.

But if you find that your new dog is barking, growling, or running away from you, you can still do a lot. First, give your new pooch plenty of space and some control. Let him retreat to a quiet area and rest as he chooses. Do not force him to come to you. Respect his need for space.

If your pup is more comfortable hiding under the sofa for a few days, let him do this. Make sure he is not disturbed while eating. Speak gently and do not punish him for mistakes, but always use positive reinforcement to train and guide him.

Next — Win Your Dog’s Trust, Train, and Socialize Him

If your new dog does bare his teeth or growl, this is a warning. He is probably frightened of something. You can just back off and speak in pleasant, upbeat, and quiet tones. Place treats or dinner on the floor, then move away. Let him move toward the food when he feels more secure. If your new dog has difficulty settling in after a few days, consider bringing in a trainer to help.

Once your dog has settled in and trusts you, obedience classes will continue to help reduce his fear levels. Dogs really do want to please and connect with their owners. Therefore, group classes can be a great way to bond and better communicate your expectations. This will help your dog feel more secure. Additionlly, classes teach a dog how to socialize in a controlled, safe environment.

Final Thoughts

In most cases, a shelter dog is usually thrilled to be adopted and have a new, loving home. And most shelters and rescue groups do their best to help dogs heal and recover from past challenges. Therefore, aggression is usually not a problem when adopting a rescue dog. To learn more, read my post How to Train Your Rescue Dog to Overcome His Fears.

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