I just dont know what to do anymore

You'll find this is a common problem. Leash Aggression (LA).  My little JRT mix is the same way. Fine with other dogs, as long as she doesn't have a leash on.

There is a lot of discussion on the reasoning behind why dogs have LA. One being the dog equates the leash to bad things.  Another being that it's a territorial/resource guarding thing.  

I'm of the opinion of the latter.  And I've worked very hard with my dog to get her past this.  I use a lot of treats and have more or less managed to get her to 'ignore' other dogs while on leash, using treats and redirection. First you'll have to know how far away the dog is when the dog begins to freak out. Is it 10 ft. 20... as long as it can see it?  If that's the case, take the dog out by itself and put it in a sit. And feed it treats (small, small portions) rapid fire as long as it ignores the dog as soon as it freaks out, you'll need to redirect the dog, either walk away... or put it back in a sit... as soon as you have it's attention, rapid fire treats. You may want to give this a command, mine is "leave it."  She now pretty much ignores other dogs while on leash, unless they come into her idea of a territory, in which case, I start over with the redirection and "LEAVE IT!" and usually it snaps her out of it. As she's truly more motivated by food than barking at another dog.  So you may need to find very, very special treats that you ONLY use when it ignores other dogs.  Once your dog is ignoring other dogs make sure you don't just stop cold turkey with the treats.  Wean him off of it and carry treats for that special "LEAVE IT" and he absolutely turns around walks away.  Big lovings and some livers for that! :)

I'm sure you'll get other advice, but this has worked for me.  Good luck!

 

Good advice!! Sera_J's method worked well for my dog and me when we were working on getting Rascal to stop growling at people while out on walks. It's not a quick-fix method and takes a LOT of time and patience, but I've found it to be very effective and to have long-lasting results. 

leash reactivity. get the book "click to calm" and follow the protocol. It works.

Kudos to you for having such a well behaved pack of dogs

Normally, most people advise introducing on neutral territory first, but it seems you've done fine integrating them anyway.

I think that the "leash aggression" sometimes comes from feeling insecure.  When he is loose, he always has the option to run away if things get hairy, right?  The precious option of "Flight" is denied once he has his leash on.  I think that is an important factor.  So some basic confidence building exercises would be a good idea, IMO.  Do you go to a class with him?  Do you do any activities together?  What games does he enjoy?  How much time do you spend training him?  Have you tried a clicker? 

On the other hand, it sometimes comes from frustration that he can't reach the other dog or person or whatever....  You are in a better position to read this than me, obviously!  Just throwing some ideas out there to consider.

Either way, this approach is a good one, because your aim is to get him to relax and be able to listen to you.   I also have a dog that is not keen on other dogs when on lead, and I did something very similar and it worked brilliantly.

It's my understanding the LA/leash aggression is due to flight or fight.  Dogs are evaluated as Alpha, Prey, Flight and Fight.  When a dog is on a leash they feel trapped so they become aggressive as a response because the flight part is not possible.  These same dogs, when loose don't have the same anxiety because they are free, therefore flight is possible.

I don't have any expierence with this type of behavior but I know its been discussed many times here on I-Dog, do a search.  The book recommendations are good ones as well.

 Good luck!!

mudpuppy

leash reactivity. get the book "click to calm" and follow the protocol. It works.

Yes it does - and it's a great protocol for obedience for ANY dog, and in easy, step by step form.