hi welcome to the forum, so your dog is showing aggesstion towards other dogs, what is your dog like on the lead dose he pull or dose he walk to heal, if he pulls you to get to other dogs, i would try him on a dogmatic it is like a halti but more softer for the dog and will give you full control over his head.

i would also consider muzzel training more for saftey for yours and other peoples dogs, if your dog as not wore a muzzel before dont just stick it on and expect your dog to like it, you must train first and make it fun with treats, i would then get the other dog you want to make friends with and walk with your dog at the side of you and other dog at the other side so both humans are in the middle of them both and do this for as long as it take remember to stay calm relaxed he will not be able to hurt dog as he will be wearing the muzzel once you have that then you can take a step further.

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