Aggression towards other dogs

Hi Jbecke, thanks for your post,
Dogs who have not been well socialized often do not understand doggie body language and this can lead to a lot of confusion and often one or both dogs getting the wrong message and getting upset. Also dogs that aren't that used to being around other dogs may be quite fear full especially when other dogs approach them on the lead because they may feel they can't escape.

For your situation I would recommend a head collar to help with socialization. These are sold under many brand names including halti and gentle leader but are basically all the same. The idea is that instead of the collar going around the neck the collar goes around the nose but also has a part that clips behind the ears to hold it on. The lead is attached to a ring that hangs under the nose and when the dog pulls the nose band tightens. This is no way hurts the dog it is just annoying for the dog like someone holding your nose. However the main idea of the design is that the dog is attached to the lead via its nose and head rather than its neck and shoulder area where its powerful muscles are. The dog cannot pull you using only its nose so you can assert full control over the dogs behavior. Also if you pull directly downwards on the leash the head collar will close the dogs jaw which can decrease the chance of biting. (However if you feel at any point your dog may bite always put a muzzle on.)

While wearing the head collar the dog cannot pull you towards other dogs on walks etc so it learns to react more calmly to the situation and also to look to you for guidance as to how to react because you are in control of it. Because of this the head collar is a great socialisation tool. Take him for walks on it as often as you can, initially to areas with few dogs and people later to areas with many people and dogs. Go for a normal walk and be calm, if you tense as another dog or person approaches your dog will interpret this to mean that you the pack leader also think is a problem. As the dog or person gets closer you dog may attempt to growl and lunge. Make sure you are holding the leash vertically so the head collar can control his behavior. As the other dog approaches continue to walk forward calmly, ignore your dogs bad behavior and continue to walk on, but as soon as it stops and your dog is calm praise him warmly. Trying to use treats in this situation is probably not appropriate as he may snap at your hand in his excitement over the other dog. Continue to praise calmness and ignore bad reactions. Walk calmy and firmly onwards and you dog will have to follow.

Once your dog has been out and about regularly on the head collar it should become desensitized to other people and other dogs away from its house. Once your dog is reliably ignoring other dogs walking past you can ask someone you know to walk your dogs together or consider advertising for someone at your local pet shop or vet clinic. Walk your dogs nearish to each other and if your dog stays calm praise him and allow the other dog to get closer. As soon as your dog shows signs of being agitated remove it from the situation and other other dog by walking back the other way for a little bit then walk back towards the other dog if your dog remains calm praise and continue to approach if it becomes agitated turn back away. Once your dogs are walking nicely together over several walks try taking them to an open space together if your dog will respond to recall. Take lots of treats or toys with you and make sure the dog knows you have them. With the other dog a little bit away let ask your dog to sit, praise and treat. Let the dog of its lead but keep its interest by asking for tricks and treating. Then introduce toys and initiate playing and free running but with recall and treats regularly so the dog is still under your control. By this stage the dogs should play together well but if your dog becomes agitated or shows stiff body language immediately recall to redirect its attention then treat. If at any time you are concerned that your dog may bite use a muzzle especially when off lead.

I hope this helps. It can take a while to socialize dogs well at this age but it will definitely be worth the wait. Let me know how you get on.