Why is my dog so aggressive towards other dogs?

I have 3 three dogs, a German Shepperd Rottweiler mix, Shi tzu, and a Golden Retriever Black Lab mix. All of my dogs are very nice and obedient, but when other dogs come over or we take them to the dog park the black lab mix will get very aggressive and attack other dogs. He has thyroid, and isnt aggressive near my dogs. I am wondering why he acts like this, and wondering if theirs a way to train him to be nice.

Try petting him and giving him treats when he sees another dog. Reward him when he is calm. When you are walking him and a dog is coming walk on the other side of the street and stop and give him treats while the other is walking pass

I might be a territory thing dogs are very territorial. If you're on a wak or something then that might be a little bit different, I recommend a a choke collar for that dog ( NOT AS BAD AS IT SOUNDS!) Its just a collar that squeeze tighter the father the dog pulls away from you so it should teach him or her not to go after other dogs pretty quick. You are suppose to give the leach a tug when the dog pulls too. It worked with my dog and once again believe me it doesn't hurt that dog it is just a poorly named device.

your dog doing a behavior that you don't approve of? Does he/she pull you around when you take him out for a walk? Does he/she bark at other dogs? Do you feel that you can't control him/her? Is it hard to take items away from him/her without being bitten?To solve all the symptoms, we must get to the root of the matter. Your dog is most likely thinking that he is the pack leader, or at least he is confused about who is the pack leader. When you claim leadership, the dog is free and content to be a happy willing follower.Your dog is less likely to attempt to harm you, your family, or other people.Your dog will not pull on his leash during walks.Your dog will remain well-behaved, even around other dogs who may or may not be.Your dog will learn to respect your possessions.Reduces constant barking or whining.Your dog will be less anxious and nervous.Your dog will be happier and more content.2Learn to think like a dog. Realize that there are some areas where dogs do think like humans, and some areas where they do not. This is important because often humans will reinforce negative behavior without knowing it.Realize that dogs live in the present much more than humans do. Just because a dog has done something for a while, doesn't mean that he/she can't change. In the same way, just because a dog has had a tough upbringing, or might have been abused, doesn't mean that he/she can't be rehabilitated into a loving, calm pet.Dogs do not have guilt or pity in their mindsets/thinking. If a human expresses these emotions, a dog will interpret them as weakness.Dogs can be given affection without being touched. A look can also convey affection.Dogs have different levels of excitability that they progress through. A problem dog that goes into a frenzy in certain situations cannot be corrected when he/she has reached his highest level of intensity. You must correct at the lower levels to prevent him/her from becoming out of control.3Learn the pack mentality.[1] Dogs have a pack mentality. If you own a dog, you are a member of the same pack that he/she is.If a human shows weakness when they first bring him/her into their pack, the dog will often try to become the pack leader himself/herself.There will always be a pack leader. If you make sure that it is you, then you'll be able to control your dog in any situation because they will look to you to see how they should react.A dog will try to become the pack leader if no one else is.Consider dogs in a pack. Dogs are happier when they know their place in the pack. Your dog will be more content and happy when you consistently behave like a pack leader. If you allow the dog to be leader in the home, but want to be the leader when you want to take him/her for a walk, you will frustrate your dog.A pack leader ... Decides where the pack will go.Decides when the pack will eat.Decides who gets what food.Decides who is allowed to bark and when.Decides when the pack is allowed to play.Decides what the pack is allowed to play with.Decides how other members of the pack must behave.Decides who owns what.Always walks in the front.Can take anything away from any dog in his pack and claim it as his own.Never says he's sorry. The 'Three Amigos' smiling for the cameraThe rest of the pack is not resentful of how this works. To them, it is normal. If you modify your behavior to fit to this model (when relating to your dog), your dog will be content because his/her pack is working the way his/her instincts say it should.When pack leaders correct other dogs in their pack, they are rarely aggressive, but just assertive. Humans must learn this combination of calm assertiveness to master their role as the pack leaderThere are exceptions to the human, as the leader, always being in front. When the dog is working, he cannot be the leader. For instance, sled dogs... they are in front, but they are also working.4Be calm and assertive when dealing with your dog. Assertive is different than aggressive.for further help please look at the web site listed below

he might just be overly protective of you. remain near him and pet him and talk to him. give him treats when he is good.