Getting Two Dogs to Get Along

I'm not a behaviorist, but yes...in my opinion getting them neutered would be the FIRST step. But really only a first STEP.  Obviously it doesn't make agressive dogs unagressive...so it may be possible they'll never get along, but introducing them properly would be the second step after neutering.  You can just put them in a room and expect them to like eachother.  Introducing (or in your case re-introducting) them in a neutral spot might help.  Are the dogs agressive towards any other dogs?  I would try and see if they can slowly be introduced outside the home and get to know eachother.  Neutering won't change any dislike they have for eachother, and won't change their behavior a lot...but there might not be as many hormones raging around.

Good luck!  You're a brave person!  I've always had a male and a female...and never had any agression issues. I spay and neuter as soon as possible so that marking, and hormones don't become a problem.  So I don't have a ton of experience...but I'm hoping a behaviorist might pop on here and tell you how to introduce them slowly and nicely.

Neutering is a first step -- but honestly it should have been done before now.  Now it will prevent a lot of health issues, and yet it will take some significant time for the testosterone to get out of their systems.  AND they have to relearn everything.

But honestly -- youre post really leaves me wondering many things -- where do these dogs sleep?  why do you HAVE the second one if it's not allowed to be at home and part of the family. 

Essentially you are setting them up NOT to get along.  The one is not socialized as a family member so he's likely battling the other for domaince all the time.  You have to set things up to succeed not fail and if he's constantly battling for your attention and to figure out what his place is it's defeated before it begins.

A plan to keep them separated, AS YOU TRAIN, but also to make sure the second dog gets appropriate exercise and stimulation is what you'll have to do.  If you don't have time for the second dog and really don't have a place for him then would it be in his best interests to simply re-home hime where he'll get the attention and care he deserves?  It's honestly not fair to set him up to fail this way.

Yo have two dogs that are bred to work -- and you have the more aggressive/independant breed set up to be submissive to the retriever.  Who is the alph in the household honestly should be up to THEM ... not you.  Unless you really don't want the pointer in the house or as a pack member. 

 Ditto what the others said - first thing to do is neuter both dogs. 

Yes, definetly get BOTH dogs nuetered. After that, let them mingle when you are carefully observing them. Scold the dog who initiates a fight and put him in another room with a closed door and leave him there for 5 minutes. The other dog who didnt start it gets quality time with you like petting, belly rub, treats etc.. Once you get to the point where neither dog tries to make an agressive move for 30 minutes praise wildly.  It might take some time but I think they will learn. There is some male dominance going on and when they work out who is above the other things will be okay.

Good luck :) 

 Oh, and also even if they do work it out still observe them carefully and never leave them alon together until you can completly, 100% trust them.

 It is extremely hard to bring an intact adult male into a house with an intact adult male. That said, it can be hard to bring any adult dog into the house with another adult dog even if both are neutered (especially if they have a history of disliking each other).

 I would go about things a bit differently than has been suggested, with or without neutering (which may not fix the issue anyway and will take at least a month to show any effects on the dogs).

 I would first suggest a very strict NILIF program, such as Susan Garrett's Ruff Love for both dogs. I would have both dogs one this for several weeks before I attempted any sort of introduction. Instead of taking them to a neutral area and just seeing how it goes, I would start their introduction by walking them together maybe even on GLs to start. You would need another person to help with this, as you would want to start with them not having any contact such as sniffing. I would make these walks extra fun for both dogs with lots of treats. I would also set aside time a few times a day to have both dogs on lead in the house being treated constantly when they are in the same room, then remove one and stop treating when they are not. I would gradually get them to the point where they can walk side by side and be happy and calm together and where they are both eager to be in the same room together because they associate with "good stuff". Then I would start allowing them to be free together outdoors with long lines at first. I would have them free indoors only after they are friendly with each other outdoors (smaller space = more chance of issues).

 It may seem like a lot of work but IMO if you want these dogs to live together happily you should take steps to ensure they not only learn to tolerate but like each other. It is better to put in a couple months of hard work than have to play RotatOdog for 10+ years.

 Was an introduction on neutral ground tried at all?  I think it's likely that it's (at least in part) a territorial issue.

I am very skeptical of the use of neutering for behavioural problems.  Not saying "it won't work" - only it MIGHT not, and when I had my dog snipped (for a different reason) it made his behaviour issues worse.  I am also not convinced that it is necessary to alter their behaviour, either, and that if the training aproach is the right one, it will work regardless of whether the dogs are neutered, but that is ONLY specualtion on my part, and not a professional opinion   I would want to ask two different behaviourists/trainers for their advice on whether neutering is a good idea or not, in your particular situation, before making a decision.

I agree that you need to try to get these dogs at least LIKING each other and I really like AG's suggestion of feeding treats while in the same room!  Take care though, and make sure both dogs are completely under control, one human per dog.... the last thing you want is snarkiness due to resource guarding over food or treats.

Do these dogs have crates?  I would also want to help them associate each other's scent with GOOD STUFF - I guess this would make a positive difference because dogs "see" so much with their noses.  So, I would get a couple of old towels.  Give the GSP a really good rub down and leave the towel in the GR's crate/bed (private space).  Give the GR a really good rub down with a different towel and put that in the GSP's crate.  Then ensure that good things - high value treats, chews and meals - all happen inside the crate, replenishing the scent regularly.

Most dogs also find walks to be high on the list of GOOD STUFF, so I would want to do walks with them together if possible as well.... I would choose neutral ground if you possibly can.  And I would emphasise that I think this is only worth doing is you have one person per dog and both completely in control.  I'd want to walk the dogs like this at first: ABBA - where As are dogs and Bs are people.