New puppy aggressive towards older dog..

I know someone is going to ask -- are any/all of these dogs intact?  Which ones?  yes, it could make a big difference.

Whoops I forgot to mention that.

 All are intact. I would consider getting the new puppy neutered but my parent's dogs and my girlfriend's will not, which I think may be less effective? My vet also advised not to neuter until 1 years old.

JHNguyen89

A fight seems to break out almost everytime we come home from the dog park as soon as we set foot inside the house. It begins with a stare, then a fight.

Not uncommon and especially with the breeds you have co existing.  Manage homecomings by taking in one dog at a time and crating that dog out of sight of the other dog.  Bring in the second dog and crate it.  Go about your business and ignore the dogs. 

You could very well have a serious problem brewing.  Consult a behaviorist now before the situation escalates. http://www.associationofanimalbehaviorprofessionals.com/

Can't really comment since I can't observe what's going on but with regard to neutering, I would not bank on that making a difference.  There are plenty of people that have multiple intact males, even breeds known to be more dominant and dog aggressive, and never have problems and there are just as many people with neutered dogs who cannot co-exist.  I don't think it's a bad idea but I would definitely not consider neutering my dog only for the reason that it might help with resource guarding.  It may or may not help at all and that is something that will need to also be addressed with training and management.  I think the vet is correct to recommend you wait at least a year so the dog can mature with proper hormones and growth.  My viewpoints on neutering are probably in the minority though.

Whenever you find yourself on the side of the majority, it is time to pause and reflect.
Mark Twain 

All I can do is offer my experiences.  When GSD Heidi was a little over 2 years old, we brought home rescued GSD mix Bruder who we figured was almost 1.  They got along famously right off the bat.  Although after a few days Heidi was wondering why this newbie was still hanging around.  The very first time I took all the dogs for a group walk, Heidi hung back behind us sulking the whole way.

But soon...she realized he was staying and the walks progressively got better.

I was feeding them all together...about 10 feet apart...but when I prepare meals...they sit close to me.  After about a week....Heidi didn't like the fact that he was still here (I suppose); and when they were all close to me as I prepared...a fight broke out.  So, I fed them separately in kennels.  They were next to each other, could see each other.  I did this for a month or so...then slowly started weaning them back to feeding them together...as I said, though they ate (and still do)...about 10 feet apart.

Every thing was hunky dory....then after Bruder was with us about a year...he started testing the waters to see if he could raise his level on the totem pole.  It happens.  Packmates will try to see if they can move themselves up in the chain.  That was short lived, when he realized that Heidi had placed her self as topdog.  He now knows his role.

So, my point in all of this is Oliver might be testing the other dogs trying to prove to the others he wants to be topdog.

I'm no trainer...so I certainly don't want to offer advice.  But, we have some awesome folks here on this board who can offer advice.  Good luck! 

Bull Terriers are on my bucket list of dogs.  Would love to see pictures of your Oliver.

Oh, and I'm on the side of neutering and spaying after the dog reaches maturity (18 months) if at all feasible.  In other words...no chance of escape or accidents.

 Thanks for the replies and helpful information everyone.

 One thing I should mention is that we've had the Jack Russell Terrier for awhile and since he was young, he has been able to roam around the house all he wants. He does that at my apartment while the Bull Terrier puppy (Oliver) is sitting in his crate. He has slowly stopped whining and 80% of the time sits in his cage quietly. However, I do notice that he's been staring at the Jack Russell Terrier walking around quite a bit (the kind of stare in which I'd expect a fight to break out). Am I making a big mistake by doing this? I often cover Oliver's crate with a blanket so he cannot see which seems to help, but I'm sure he knows that the JRT is roaming around. I could crate the Jack Russell but since he's never been crated very much in his life, I think it may be difficult to train him to stay in there without whining.

The JRT seems to be fairly dominant and/or protective, but seems to get along with dogs very well. At the dog park he does fine with all dogs. In fact, he seems to do fine with the Bull Terrier Puppy (Oliver). BUT, when Oliver snaps at him, he WILL snap back. I am noticing that the Jack Russell Terrier is always hesitant to do things when around Oliver (inside the house).

Any suggestions would be greatly appreciated. It's a very difficult situation because I'm afraid to let my girlfriend stay alone to babysit the dogs. When a fight breaks out, it's difficult to pull them apart and sometimes we end up injuring ourselves. At the same time, they do so great with each other when NOT in the house.

Here's a photo of them outside:

I dont have much advice to give, but I did want to comment and add my 2 cents on the Bull Terrier in the crate and the Jack Russell walking around doing whatever he wishes.

Honestly, to ME I think this is unfair. I have a boxer and my ex has a AB (we still live together) and my dog is crated while his isnt. However, my dogs kennel is in the bedroom and when my dog has to be in there, I will close the door to the bedroom (with music playing of course). That way, the other dog isnt walking past him going to and fro.

This may be more of a personal reason and maybe *I* am the one that finds it jealous for the other dog, but it has always worked out and I have never had an issue with aggression from my dogs.

lol ALL Terriers are dominant on some level, possessive on some level and dictatorial on some level. That is why Terrier people, love Terriers. They are walking attitude. They spar them in the ring to show that characteristic off. MOST Terrier breeds can be same sex TOLERANT with proper training but few really LIKE same sex dogs...especially other terrier breeds.

I would actually prepare for things to escalate since the younger dog is coming into his adolescence and that is just annoying in ANY dog a lot of the time. He SHOULD in theory be allowing the leadership of the older dogs because he is older. But that he isn't backing down from the stare...tells me he doesn't share that opinion.

The pup thinks highly of himself...put him on NILIF training, make him work for every scrap of attention he receives and do not tolerate his boorish antics. Timeouts, ignoring, can work well. He should not be upon furniture or beds without a command and OBEYING that command. He should learn the "place" command so that when he gets snarky looking he can be sent away from whatever is provoking him to his bed area and chillax.

Permanent gate community style separation, may be in the future, but hopefully not. Terriers are always Terriers...whether they have dangly bits, or not. IME. 

 @boxermom2Marley, I can definitely see where you're coming from which makes me feel that my own situation is unfair to the Bull Terrier in the first place. However, I also think the Bull Terrier is being unfair to the Jack Russell Terrier in many ways as well (toys, food.. etc) so I'm not sure how to go about that. And also, the fact that the JRT isn't used to staying in a crate in the first place.

I will try the crate thing forawhile and see how that goes.

Thanks!

Dogs don't have much concept of fair.  Resource guarding is normal dog behavior.  Don't leave it up to the dogs to settle who owns what.  Feed separately and don't leave toys laying around. 

All my dogs are crate trained and one may be in a crate for whatever reason and none show any resentment to the other dogs who aren't crated.  If a dog is properly introduced to the crate, it's not a place of punishment. 

As I said earlier, and I say it even more forcefully now after reading that the dogs are full on fighting, you need a behaviorist consultation or commit to keeping them separated in the house if you don't want to spend the money on a consult.  The future vet bills will probably cost a lot more than having someone come in and assess the situation and help you learn how to deal with the dogs.

 I'm definitely looking into a behaviorist that fits into my budget at the moment.

I've talked to one behaviorist and had first time consultations with a few trainers trying to decide which would work best for me. I've found that many of the trainers tend to say that with two intact males I'm just asking for trouble. Where as the behaviorist I had talked to mentioned that it may help but is not necessary. The behaviorist mentioned a retreat in which I would leave my puppy with him and his dog for 2 weeks as socialization is key. However, he mentioned that with a puppy who is 6 months will never get along with an older dog like my girlfriend's Jack Russell Terrier. Meeting up with the trainers/behaviorist I'm left a bit more confused than I was before.

Though I should mention that the behaviorist was not on the AABP list. Perhaps it may best to consult with one with the right credentials for the best results..

Again, thanks for the information and I look forward to hearing more tips from everyone.