Jack Russell Terrier

Question
I have a female Jack Russel Terrier that is 5 years old.  We have had her for almost 4 years.  She is super smart.  She had a 3 pups 1 1/2 years ago and we sold 2 and gave one to family because we were going to keep one but fell in love with the father and ended up keeping him.  She has always been a "queen bee", snappy at our other Jack Russell and our lab.  But it has seemed to get worse in the last year.  She used to snap at the other dogs but then walk away with her head held high like "so there!  I am the boss".  But now she will attack them.  SHe is really mean and will not stop unless we physically stop it.  No amount of yelling will stop it.  She is trained well except for this.  She will not stop and has hurt our old lab and the other Jack Russell to bleeding.  It is out of control.  We have an underground fence and tried the training collar, to no avail.  We are considering getting rid of her but our son is devistated.  She is NOT fixed, do you think that would help?  When we get her off the bleeding dogs, we tell her she is bad and put her in her kennel.  HELP!!!  Thank you so much

Answer
What has occurred is that she has learned this behavior is acceptable because you allowed it and set no boundaries.  An electronic collar will work if used properly.  Your current approach of dealing with it by removing her after the fact and putting her in her a kennel is only escalating the situation because the dog has no way of knowing why it is being put in the kennel.  Sure it avoids the attaching because the dog can't when it's in the kennel.  The first step would be to get a muzzle to stop the obvious from happening and then you can deal with the situation without putting the other dogs in harms way.  You will need to use a standard behavior extinguishing process combined with the ONE, TWO, GOOD DOG! protocol to teach the dog that this demonstration of aggression is unacceptable.  Here is a simple protocol to follow:
With the muzzle properly fit and the dog on a control lead such as the "whisper string" create a situation where the dog begins to demonstrate the behavior.  You may do this by putting the dogs together or whatever usually sets her off.  When the aggression becomes obvious use the lead to cease the behavior with a firm jerk at the same time you vocalize a loud firm short "a" sound "AAAAAAAAAH".  When this action is at the proper level of intensity it should immediately cease the aggressive demonstration. When the dog's aggression stops praise it immediately.  This entire process will take no more than 2 or 3 seconds with praise extending for another 2 or 3 seconds.  Praise should include both vocal and physical.  It should also be firm and purposeful with strong patting of the chest and sides.  Do not stroke the dog down the back or pat it on the head.  This praise should occur almost instantly with the dissipation of the aggression.  Repeat this process 15 or more times in 3 to 5 minutes.  Get the reps even if the dog stops demonstrating the aggression after 4 or 5 times.  Just continue the process for at least 15 reps.  If there is no demonstration of aggression gradually eliminate the "reprimand", first stop the jerk then a few reps later stop the "AAAAAAAH" and just praise the dog for accepting the situation.  Again remember the time frame is very important!  The entire process only takes a couple seconds.  If you still have the electronic training collar you can use it instead of the reprimand described above.  If you do use the electronic collar you will need it properly fitted, long probes on the receiver, fitted very snug just under the chin.  If you use the collar correctly it will definitely stop the demonstration of the behavior.  Even using the training collar you still need the reps.
Once the dog is responding to this then you can repeat it without the muzzle.  As a professional I would not use the muzzle with this size of dog if I were personally doing the modification but as a novice handler you need to use it to avoid making reactionary responses when the aggression surfaces.  This way you can relax and not have to worry about the dogs being harmed.  Through this process the dog has also learned that the "AAAAAH" sound means to stop what its doing.  Therefor you can now use the "AAAAAAH" anytime this type of behavior begins to surface.  Always remember the praise when the dog stops.  Also occasionally praise the dog simply for not demonstrating the aggression when in the past it would have.
Just a few of these 5 minute sessions applied during different circumstances and you will have the situation under control.  
Here is how it fits the ONE, TWO, GOOD DOG! protocol:  The reprimand (ONE), the dog ceasing the aggression (TWO),  Praising the dog (GOOD DOG!).  This should solve your problem as well as give you an idea of how this protocol can work for any situation.  You can visit my website and purchase my booklet covering this and other issues with the "ONE, TWO, GOOD DOG!" protocol as well as the "whisper string".  http://invincibleservices.com/html/one__two_good_dog_.html
If you continue to have issues please call.  Dr. Hogan 509-991-0385 until 10pm pacific time