http://www.caninedevelopment.com/Sibling.htm
1. i suggest that they have 2 separate crates
2. i suggest walking them separately
and letting them eat away from each other
that will help you bond with BOTH of them separately .
as for the fighting, i dont know. but i encourange games that will make them work together and have fun, another good way to avoid fights, LOTS OF TOYS, and if there is one they both like, get another one of the same type. toys, food, and attention are the 3 things that dogs will usually fight over.
Fighting:
If you need to break up a fight, squirt the dogs with water or make a loud noise to distract them. Never attempt to break up a dog fight by grabbing the dogs by their collar or getting in between them. Grabbing dogs whilst they are fighting can result in what is called "redirected aggression," where a dog bites you because he thinks you are part of the conflict.
Sometimes the problem can be resolved if, instead of protecting the underdog the owner supports the hierarchy ie the top dog. Firstly determine who is the more dominant, reinforce that position by feeding, greeting, playing or letting the top dog out first. Usually this will help, but not always. “The problem with that approach is that it’s often difficult to tell who should be the alpha dog, it is also difficult for owners to play favourites with their dogs.
Two Choices:
To my mind you have two choices with siblings from the same litter or two young pups from different breeds, Whilst I believe the first solution is the most practicable, which is to re-home one of them, I am also aware it is the hardest and most difficult for the owners. If not they will always be damaged by their almost total reliance on each other.
If you decide to choose this alternative, you can home one of the dogs with another family member or a trusted friend. You will see dramatic improvements to the personalities of both pups. These changes occur almost immediately. Be aware that the longer you delay the harder it will be to part with one of your pups. It is a difficult and agonising decision for someone to make, however in the long run it is in yours and ultimately both your dog’s best interest.
Your second choice is to create two individual dogs, with two separate identities and personalities, without the total reliance on each other that normally happens in these situations. To do this you will need to work twice as hard because all the things you did together you will now need to do totally apart.
Things you must do:
Everything must now be done independently to allow for the Siblings to have any chance of becoming separate entities instead of the reduced sum of the whole.
- Play with them separately
Literally everything you do should be separate. That includes Puppy and Training classes, take them to a trainer that understands the inherent difficulties of raising two puppies together. Take them on separate nights hopefully to the same trainer. They can play together but only at strict designated times and for a period of no more than 15 minutes each designated play time.
This regime will not be for life as the pups will, after a period of about 12 to 14 months have formed their own personalities and temperaments; at this age they will have become confident of their own individual abilities. Not as in most cases total inter-dependence to each other when siblings are raised, trained, and fed together.
Without the total reliance on their sibling for constant support they will grow and blossom into much rounder and less aggressive and fearful individuals. I cannot stress how important it is to separate the siblings until they are older. It will produce two individuals rather than an impaired two parts of the whole.
It is worth stating that it is not only siblings that have these problems. If you raise two young pups from different litters or even breeds, you can have similar problems. I always recommend my clients to wait till their puppy is 14 months old before purchasing another puppy this then allows you to concentrate all your efforts on that individual and hopefully it will take on some of the good traits of the older more experienced dog.
I think what truly annoys me are the breeders that sell siblings, and in some cases actually use emotional blackmail to push two pups, For instance " what a shame you can't take two as I may have problems as he's so small/white/little/runt etc and I'll probably have to have him put down in the end". I have no respect for a breeder that uses these tactics or that sell littermates to one owner. If they are experienced and not a first time breeder then they are well aware of the pitfalls of these actions, and that the dogs will suffer for the rest of their lives
http://www.doglistener.co.uk/choosing/siblings.shtml