2 of my three dogs who are all brother and sisters, a male and female attacked the other female on christmas day and really hurt her she ended up dying on boxing day, The attack was so vicious that we got the other 2 put to sleep. Which we thought was the most safest thing to do. Can anyone tell me what would make these 2 do a thing like this to their own sister who has lived and breethed with her for the last 1.5 yrs or was it just animal instinct that took over. As you can imagine my heart is broke at losing my 3 babies.

Maggie

Oh Maggie what a terrible thing to happen to you i'm awful sorry.  Dogs when fighting will gang up on the loser:rolleyes: 

Warm regards Susan

I'm so sorry to hear your news. What a dreadful shock. Had they ever fought before, or was it completely out of the blue. What breed were they, by the way?

It is all to do with hierachy generally/  Havng dogs close in age, especially siblings, means there is no easy way to determine rank so they fight it out.

This is the most serious reason why you should not have more than one pup at a time.

Also some breeds are more dog dominant than others,a dn shoudl never be left alone unsupervised.

Living in a confined space like a house gives the looser nowhere to go, so in effect it is not doing what it would in the wild backing down, so tehy keep fighting.

Why did you think it necesary to put the other two to sleep? 
dog to dog aggression has rarely anthing to do with a danger to people (unless they were unreliable in this respect).  I can understand how you couldn't face living with them anymore.

I'm very sorry, that is awful. I know how hard it is when bitches fight. Did you ever get all of the dogs neutered? Apart from the usual problems that do often occur when you have the same sex dogs of the same age, the fact tha both your bitches were mated by your dog  I would have thought could also play a part as even though I presume they didn't have puppies (?) it will have increased the rivalry between the two bitches.

Maggie24, so very, very, sorry about what happened on Christmas Day of all days too, I just wish you had asked people's opinions on this site first though, before putting your other two dogs to sleep. I think the majority of us would have advised leaving the other two dogs be, they would probably have lived happily together, in house fighting can kick off for all the reasons that Brainless has said,  I guess it was the shock of them killing your other bitch, I can understand your feelings and the immediate horror you must have felt, there is no going back now I know, but it is a shame.  It is a warning to many about the dangers of young bitches together.  So very, very sorry, what a horrible thing to happen.

So very sorry to hear about awful situation you have found yourself in.

Dont think thier is any point in looking back at alternative solutions to what happened you did what you felt was right.
I can only send you my deepest sympathy for your loss and hope that time will heal your sadness.

Roni

Well said Roni that's why i never mentioned it, the decision has already been made.

Warm regards Susan

Maggie

Sorry to hear what has happenend . I currently have a JRT that is 'attacking' my Mastiff's and my Rottie.
He used to fight with his brother until my daughter took that one away when she left home. There had been no problems with the other four living together for almost a year, even tho' we introduced the Rottie recently, until New Years Day.
On that day, my son home alone with the dogs, the JRT attacked the Bullmastiff. The Rottie tried to protect the Bullmastiff but my lot never all jump in.
Luckily there were no injuries other than the nip the JRT gave my son when he seperated them. The bigger dogs don't fight back they try to get out of the way.
It happened again last night  when we were all in.
Again, luckily, no serious injuries. This is because the bigger dogs 'leave' when told but everytime they 'left' the JRT dived into one of them.
I'm not having the JRT PTS but I have made the decision to re-home him. Even tho' the Rottie was the 'last one in'.
I fully understand why you did what you did. It must have been terrible for you to make that decision.
I think we all learn by our mistakes. I know I have. I'll never have siblings together again. Although in the long run my boy is being re-homed because of fighting with non-siblings I think if I'd not had him and his brother together initially then he might not have become aggressive with the bigger dogs.

My JRT is going to an experienced JRT owner and will be an only dog from now on. I must add he isn't aggressive when out on a walk and is the most fantastic little dog with both kids and cats.