Socialization advice please

Inquiry: I have a 8 to 9 year old Doberman mix that I rescued in 2004. I've been told that he may be an English Doberman by a vet. He has a lot of doberman in him. He is a fantastic dog in every aspect except for his behavior around other male dogs, especially while on leash. He's OK with female dogs. He's is as gentle as a lamb around humans. I could easily pull a t-bone steak out of his mouth and he wouldn't show any signs of food aggression. He was neutered at the rescue group when he was around 1 1/2 years old. 

I would love to be able to take him on group outings scheduled here, but I'm worried how other dogs will react to him. I'm also worried about other owners reaction towards me bring a big dog around others when he has this dominance problem. I have kept him away from other dogs for the past 7 years hoping that he'd finally mellow out, and he has a lot. I think a lot of his behavior is leash related. 

Do any of you have any suggestions on how to start socializing my dog? When he is off leash he used to play around with the male lab that lived behind us. The lab tolerated him well and they played around well together, but unfortunately the lab died from old age. 

The outings scheduled with this group sound great, and I'm very jealous of all of you that have dogs that you don't have to worry about.

Response: What you've described, sounds like dog reactivity. Your dog has reactions to male dogs. And he has on-leash reactivity too, which is fairly common. (01 article link below) 

Things you can do:
--Education: Learn more about dog body language (02) and about thresholds. Each dog has a different distance (threshold) at which they will become reactive. Observe and note what it might be. The 4pawsu (03) article explains thresholds.

--Management: Change your reaction and what you've been doing. Dogs have tapes archived in their minds. Each tape is a series of reactions that have become habit. When an owner/handler changes what THEY do (how they react) the dog has a hard time finding the tape to play out. There is small window of opportunity with this, as the dog will quickly adapt to the change and make a new habit. So be prepared with a training plan and change your body language, tone of voice, what you say, relax if you are tense. And any one of the following tend to make the reaction worse over time. Pulling back hard, jerking, verbal scoulding, etc.

--Training: Find and use professional guidance. Whether that is private sessions or taking classes. (05) Seek positive training environments that will help Toby learn to look forward to seeing a male dog.

--Training: Work at changing how Toby feels about other (male) dogs when he sees them on-leash. Make great things happen! The ASPCA article (04) gives a bit of insight. Click training can be powerful and fast.

--Equipment: Select and use appropriate management. Use appropriate equipment such as, "Gentle Leader." There is a training period required. Give yourself and Toby time to get used to putting on, wearing and using new equipment. (06)

Each article has useful insights. No single article says it all.

01. Reactivity explained - link

02. Dog body language - link

03. On-leash frustration - link

04. On-leash reactivity - link

05. Dog Trainer list - search this website for the word 'trainer'.

06. Gentle leader - link (search for, coaching owners to maximum effectiveness)

This is a lot to take in at one time. So please, please ask questions.

Reaction: I don't know where to begin in offering my appreciation for your help. I am greatly indebted to you for compiling this list of resources. I've read through your linked articles, and I'm hopeful that I can train the reactive response out of my dog. I am really looking forward to meeting you sometime so that I can personally thank you.