AGGRESSION - SOCIAL AGGRESSION TOWARDS UNFAMILIAR DOGS
Why is my dog aggressive to other dogs?
Aggression between dogs can result in injury to dogs and/or to the people
trying to separate them. The behavior can consist of growling, snarling, barking,
lunging, snapping and biting. It has many causes including social conflict,
owner defense, fear, anxiety or inadequate communication between dogs.
This aggression can be elicited by dominant gestures or postures from either
dog. These can include placing head, or feet on the back of the other dog, dominant
body postures such as eye contact, high tail and stiff legged approach. Owners
may inadvertently reinforce the behavior by lead tightening and vocal cues.
These may also signal to the dog that the impending approach is problematic.
Lead restriction does not allow the dog to react with a normal repertoire of
responses including body postures, approach and withdrawal. Some extremely bold
or assertive dogs will fight rather than back down when challenged. Although
dominance challenges may be a source of aggression when two dogs are meeting
each other for the first time, most dominance hierarchies are established with
posturing and not fights. It is likely therefore that fear, territorial behavior
and/or learned factors contribute to an initial attack. Dominant aggressive
dogs may be over-assertive and/or overprotective if the owners do not have good
control or have taken a subordinate position in relationship to the dog.
Territorial aggression toward other dogs
This aggression is primarily exhibited when unfamiliar dogs are on the resident
dog's property or what the aggressor perceives as his territory. Some dogs get
highly aroused at the sight of other dogs on their territory and may jump fences,
or go through windows or doors to get to the intruder.
Fear based aggression toward unfamiliar dogs
This sort of aggression is very common in aggressive encounters between dogs.
The diagnosis is made based on the body postures and reaction of the dog when
faced with another dog. The fearful dog will often have the tail tucked, ears
back and may lean against the owner or attempt to get behind them. They may
be barking at the approaching dog and backing up at the same time. Often the
dog is avoiding eye contact. This behavior may be precipitated by previous aggressive
attacks from which the dog could not escape and sustained injury. Owners that
try and calm their aggressive dog may serve to reinforce the aggression, while
those that try to punish the dog will only serve to heighten the dog's fear
and anxiety in relationship to the stimulus. Good and effective control can
help to calm the dog, while owners who have their dogs restrained on a lead
(especially with a choke chain) and have poor control often have very defensive
dogs. Dogs that are restrained on a lead or tied up are more likely to display
aggression when frightened, because they cannot escape.
Learned components of aggression
Learning and conditioning aggravate most forms of inter-dog aggression. Should
threats or aggression result in the retreat (or removal by the owner) of the
other dog, the behavior has been reinforced. If the owner tries to calm the
aggressive dog or distract it with food treats, this may also serve to reward
the aggressive behavior One of the most common mistakes is to punish the dog
that is aggressive toward other dogs. This usually serves to heighten the dog's
arousal, and teaches the dog that the stimulus (other dog) is associated with
unpleasant consequences. Many owners, in an attempt to gain more control, then
increase the level or type of punishment (e.g. ever more severe jerks on the
lead) which further heighten the dog's arousal and in some cases may lead to
retaliation and defensive aggression directed at the owners. If the dog to dog
interaction results in pain or injury to one or both dogs, the dogs will quickly
learn to become more fearful and aggressive at future meetings. In short, if
the owners cannot successfully control the dog and resolve the situation without
heightening the dog's arousal or increasing its fear, the problem will progress
with each subsequent exposure.
How can I prevent my dog from becoming aggressive with other dogs?
Prevention starts with puppy training and socialization. Early and frequent
association with other dogs will enable your pet to learn proper interactions
and reactions to other dogs. This can be very helpful in the prevention of aggression
to other dogs.
You must have good control of your dog. Your dog will take contextual cues
from you, and may be calmer and less anxious when you are relaxed but in confident
control. Moreover, the dog should reliably respond to commands to sit, stay
and quiet. If necessary, the dog may need a head halter to give you additional
For territorial behaviours, it is most important to prevent the dog from engaging
in prolonged and out of control aggressive displays both in the home and garden.
Aggressive displays include barking, lunging, fence running, jumping on doors,
windows and fences. These types of behaviours should be discouraged and prevented.
One important component is teaching your dog a "quiet" command for barking.
My dog is already aggressive to other dogs. What can I do?
First and foremost, you must have complete control over your pet. This
not only serves to calm the dog and reduce its anxiety, but also allows
you to successfully deal with each encounter with other dogs. Leads are
essential and the use of head collars and/or muzzles is strongly recommended
for dogs that will be in situations with multiple dogs.
Begin by establishing reliable responses to basic obedience commands. If the
dog cannot be taught to sit, stay, come and heel, in the absence of potential
problems, then there is no chance that the dog will respond obediently in problematic
situations. Reward selection can be critical in these cases, since the dog needs
to be taught that obedient behavior in the presence of the stimulus (other dog)
can produce favored rewards. The goal is that the dog learns to associate the
approach of other dogs with rewards.
Long term treatment consists of desensitization (gradual exposure) and counter-conditioning
the dog to accept the approach and greeting of other dogs with obedience and
rewards. This must be done slowly, beginning with situations where the dog can
be successfully controlled and rewarded and very slowly progressing to more
difficult encounters and environments. The first step is to perform training
for its favored rewards, in a situation where there are no dogs present and
the owner is guaranteed success. Food or toy prompts can be used at first, but
soon the rewards should be hidden and the dog rewarded intermittently. The selection
of favored food or toys is essential since the goal is that the dog will learn
that receiving these favored rewards is contingent on meeting other dogs.
Once the dog responds quickly and is receiving rewards on an intermittent
basis, training should progress to low level exposure to other dogs. If the
owner's training and the rewards are not sufficient to control the dog in the
absence of the other dogs, then using a lead and head collar, selection of more
motivating rewards, and seeking further assistance and guidance from a specialist
should be considered. The next steps in desensitization and counter conditioning
rely on a stimulus gradient. In other words your dog needs to be controlled,
(preferably with lead and head halter) and respond to commands and rewards in
the presence of gradually more intense stimuli.
Begin with a calm, and well-controlled second dog, in an environment where
your dog is less anxious or threatened, and at a sufficient distance that your
dog will respond to your commands. Gradually the dog is exposed to dogs at closer
distances and in more familiar locations. Using the head halter and a prompt
(reward prompt, set of keys) it should be possible to keep the dog focused on
the owner and sufficiently distracted. While dogs with fear aggression may improve
dramatically and learn to greet other dogs; dogs with dominance-related aggression
that are trained in this manner do not usually end up greeting other dogs, but
learning to walk calmly with their owners and stop initiating fights.
Dogs that are exhibiting territorial aggression should be retrained in much
the same manner, but the gradient of stimuli will need to be adjusted. Begin
in the front hall or on the front porch with no other dogs around. Then with
the dog controlled in the hall or on the porch, other dogs could be brought
to the perimeter of the property. Over subsequent training sessions, the dogs
could be brought closer to your dog, or your dog could be moved closer to the
Another way to disrupt the undesirable response and get the dog's attention
is to use an air alarm or shaker can. Once the inappropriate behavior ceases,
and you get your dog's attention, the dog should be redirected to an appropriate
behavior such as play. The greeting should be repeated, until no threats or
aggression are observed.
Success can be achieved in a number of ways, but head collars are generally
the most important tool. Head collars provide enough physical control that the
desired behavior can be achieved (sit, heel) since pulling up and forward, turns
the head toward the owner and causes the dog to retreat into a sit position.
With the dog's head oriented toward the owner and away from the other dog, lunging
and aggression can be prevented, and the dog will usually settle down enough
to see and respond to the prompt. Rewards can and should be given immediately
for a proper response (sitting, heeling), and tension reduced on the lead. If
the dog remains under control with the lead slack, the reward (toy, food, affection)
should be given, but if the problem behavior recurs, the lead should be pulled
and then released as many times as is necessary to get and maintain the desired
response. The dog's anxiety quickly diminishes as it learns that the other dog
is not to be feared, that there is no opportunity to escape, that its responses
will not chase away the other dog, that responding to the owner's commands will
achieve rewards, and that the owner has sufficient control to achieve the desired
behavior Also since there is no punishment or discomfort that might further
aggravate the situation and rewards are not being given until the desired behavior
appears, fear and anxiety will be further reduced.
Are there drugs that can help the treatment program?
Occasionally, for fear aggressive dogs in particular, certain drugs may help
to calm the dog enough so that the retraining session is successful. For situations
where the problem has become highly conditioned and intense, antidepressants
may be useful for regaining control. In most cases however, the best calming
influence is a head collar, good owner control and some strong rewards.
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