Dogs can be aggressive for a variety of reasons, and nothing could be scarier as an owner. You worry about your dog picking a fight he can't win, hurting someone else’s dog, or worse yet, someone's child. Outbursts of aggression can be unpredictable, unsolicited and not just toward others, but possibly you as an owner. It can feel very limiting, and make you worry every time you pass a stranger on the street or another dog at the park. Leash free parks become entirely out of the question, and your friends and family can never bring their dogs over. What causes behavior like this and what can you do to change it?
The Root of the Behavior
These behaviors can originate from a variety of factors. An unfamiliar environment, perceived danger, show of dominance, etc. Regardless of what is causing the aggression, it is likely they react aggressively to multiple scenarios, and often unpredictably. Another dog is often the irritant and, whether or not they perceive them as a threat, they may react aggressively. Dogs that have had early contact with other dogs and animals are typically much more accepting of other dogs and more diverse and changing situations. Dogs that grow up together are typically very docile to each other, with the exception of the occasional need to display their dominance from the alpha.
Unfamiliar dogs often clash upon fire meeting. Typically, this is due to anxiety, fear, or learned behaviors. That last is particularly important as much of it is learned, and correct behavior can be implemented. A trainer with hands-on contact is going to be the best bet to reduce aggressive behaviors. However, there are a lot of things you can do at home to help correct the behaviors and make them feel more comfortable around other animals. Dogs often respond to your behavior, so it is important you try and maintain a relaxed demeanor. Don't pull tight on the leash as your natural instincts would dictate, but rather leave it very loose, and let them approach each other naturally, on their own accord. Use your leash only if a fight is clearly imminent.
Some personal anecdotal experience; separating the house by a baby gate, allowing one dog on each side, gives them the opportunity to get to know each other while preventing physical confrontation. In this scenario, both dogs have a safe environment they can retreat to for comfort, but a way to get familiar with the other dog in the house.
Encouraging the Behavior
A lot of this comes down to the dog’s environment and your demeanor, both throughout the day and at the time of confrontation. Relax, take a calm demeanor. Don’t pull his leash tight, and let him approach the other dog so long as they aren't snarling at each other. Make sure the comfortable environment they have in the household is relatively free from stress. Maximize their comfort by giving them a particular spot in the house that is theirs. With two dogs in the same house, often the conflict is over food. Be sure to give them separate bowls, and if you give one a bone, be sure to give the other one as well. This is a rule applied to attention as well. Try not to have a black sheep in your house and try and give them equal amounts of attention.
The type of play you engage in can reinforce a lot of negative behaviors. If you wrestle and push your dog around, regardless of how harmless, reinforces aggression by encouragement. Try fetch. That's a perfectly good 'ole game. Allow dogs to approach each other on their own terms, preferably without a leash on. If you are anxious, they will be the same. If your household has a lot of perceived or actual violence, that may encourage aggression. Try to keep your kids wrestling to a minimum around the dog.
Other Solutions and Considerations
It is important to remember you are legally liable if your dog injures another person or animal, and this can result in untold amounts of legal settlements. Aggression and violent behavior need to be taken very seriously as to protect, not just the fate of your animal, but up to your entire worth. If these steps do not remove the aggression be sure to consult a professional trainer. Take your health, wealth and happiness into consideration. It's for everyone's benefit.
Assuming these steps work for you, just remember to keep up the behaviors that made the improvement! Redundancy of your best practices transforms into a redundancy of success.