Female Bull Terrier attacking other female housemate

Question
QUESTION: I have a 5 year old neutered male Irish Terrier, 2 1/2 year old male husky, not fixed, a spayed 2 1/2 year old female husky and a 15 month old female bull terrier not spayed.  
As of lately the female bull terrier is attacking the female husky.  The bull terrier does not do well against the husky and attacks more viciously when the female husky, Tonka defends herself and hurts the bull terrier Tallulah.

Tonka will hid from Tallulah, and Tallulah will seek out Tonka and attack her.  These fights have to be separated every time and Tallulah is left with multiple wounds. As am I at times.  I keep them in separate kennels during the day and they are never together unsupervised.  

Tallulah has always started fights when unsupervised so at night she has always been in a crate.  But these past three weeks, she has started the fights with Tonka.  She used to fight with the male husky, Nanook but he would fight back and hurt her so that stopped her from provoking him after a few battles.  She still tested him but if he growls or raises he lip or back fur and tallulah retreats.

So now she attacks Tonka.  At first if was nips and Tonka who hid behind me when I would bring her in, then she would take it further and finally Tonka started fighting back.  Tonka avoids being in the same room as Talluluh but Tallulah will look for her and go full on attack when she finds her.

I started keeping Tallulah on a leash in the house and preventing her from fighting.  But the minute the opportunity is there she attacks Tonka.

Tallulah tries to always be the favored dog and would run off any dog who came near us.  I though if I spay her it might help or if there is any medication for her if behavior modification does not work.

Do you have any suggestions to find peace again?

ANSWER: Several minutes after posting the answer below, I have to strongly caution you that this situation does not appear to be salvageable.  Not being able to interview you in person and evaluate Tallulah (as would a behaviorist you hopefully can find), I can't say this with 100% surety; but it certainly seems that Tallulah is quite dominant, very typey in terms of behavior, and this is a dangerous situation.  Read the following analysis but proceed with caution.  If you are unable to locate a professional, you must plan to rehome this dog.

You have a bitch (Tallulah) who is definitely attempting rank in your pack and who has now begun to attack on sight your Tonka (by the way, she also challenged your male Husky who, rightfully so, displayed real dominance and put her in her place...so far, so good.  Lucky for Tallulah the Husky "played" by the rules, or she'd be dead.)  Tonka, despite her predilection to be not engaged in dominance issues (and appears even softer than that, wishing to fade into the background) now has a fear aggression problem toward Tallulah and is most likely extremely stressed ALL the time.  You are not in control of this pack.  Tallulah does not respect you sufficiently to curtail her own agenda and, given her breed, is more likely to continue in escalation of her aggression until someone (perhaps you also) is seriously injured.  When two females go at it in this manner (even if only one of them is intending the fracas), it can be impossible to rehabilitate.  

Spaying Tallulah might help but it takes MONTHS for estrogen levels to diminish and her behavior is set.  She should be spayed in an attempt to somewhat level the playing field, but she CAN NOT for ANY REASON be trusted free in your home or you WILL have a blood bath on your hands.  Medicating her will not help; her issue is not anxiety.  Even a beta blocker (propanolol), which would truncate adrenaline, will not help; Tallulah is being driven by breed, by confidence, by temperament and by sorely lacking pack structure.  You absolutely require the in person observation and advice of a certified applied animal behaviorist.  This situation will quickly worsen.  I can't see from here what you are doing before, during and after these attacks, but you definitely have (unwittingly, this is NOT YOUR FAULT) contributed to the problem.  Call the veterinary college in your geographical area and see if you can find an expert.  If you are unable to do this, you need to rehome Tallulah.

---------- FOLLOW-UP ----------

QUESTION: I will try and find a expert to evaluate and help with this.  You mention the way I react to the fights, are there certain triggers or behaviors that I can do or avoid when this happens.  Normally I separate by grabbing Tallulah by her back legs and put her in her crate.  Which I know the crate should not be associated with negative behavior.

I do agree 100% she is trying to be the pack leader.

Thank you  

Answer
Of course grabbing Tallulah by her hind legs is the safest way (for you) to break up any active fight, and I don't blame you.  As for crating her, if you do it CALMLY with NO SIGN OF ANGER after one minute of the separation, this shouldn't be a problem (even though you are obviously using the crate to attempt to control this escalating problem.)  What I meant by your contribution is your behavior toward/among your dogs in general and how you reacted the first few times.  However, seriously, I don't think this is in any way your fault, nor do I think your contribution is a real issue.  You have a breed here that is known for its dominance and questionable ability to interact with other dogs in a peaceful manner (when badly bred, let's remember that a "good" breeder chooses breeding stock for type AND PRINCIPALLY temperament in some breeds, and this is one of them.)  Proceed with extreme caution; attempt to locate an expert; but be prepared to rehome this dog.  I would contact Bull Terrier rescue (look for the AKC breed site online); many purebred rescues have "railroad" transports, so if the foster home is not close to you geographically, this should not be a problem.  If you can find such a legitimate rescue (and do your homework, ask for references, contact the breed club secretary and ask for the credentials of the rescue), and if they are willing to accept this dog, that is your best choice.  A legitimate (LEGITIMATE) breed rescue will have experience in any behavior problems related to their breed; will have a behavior expert associated with them; will have homes waiting.  I know how difficult it will be to make this choice.  My best wishes to you.