sudden aggression in my dogs

Question
I have 3 female Chihuahuas. Their ages are 3,2, and 7 months. The 3 year old is the mother of the other two and all 3 were spayed 2 weeks ago. I have had all of them since they were puppies. They have always been very playful and good natured. They have always gotten along really well until the last week. Now the 2 year old and the puppy are constantly fighting. One minute they're fine and playing, and the next thing I know they are at each others throats growling and snapping. This happens several times a day. As of yet, they have not injured each other but the attacks seem to be getting more violent. At this point, I am having to keep them seperated. Around me and other family members, they behave the same as they always have. I have tried calling their vet several times this week but they have yet to respond to me. I am very concerned about their behavior. I love them all and would hate to get rid of any of them. Any suggestions?

Answer
Hi Mary, Although your dogs are spayed, they still go through hormonal changes and it sounds to me like the 2 year old is at maturity. She is now challenging the younger for authority in the pack. Since it does not happen when you are there, I would recommend that you get the help of a local obedience school. You should take all three to school together and get them used to working together and playing together during praise at the end of a good lesson. When any one of the three tries to show that they are alpha over one of the others, you need to step in and show them all that YOU and only you are the pack leader. When I introduce a new dog into my pack and they get aggressive or too playful with one another, I stand up and very firmly say "GENTLE", staring each one in the eyes. If I must, I will take the aggressor away and put him/her to work for a short time and then let him/her go back to the pack. Having a zero tolerance rule for any kind of aggression or rough housing is a good rule.  They can play all they want as long as there is no snarling, snapping, or biting. I make it a peaceful situation with everyone knowing that I alone am in charge, I am the alpha dog. Soon peace becomes the rule and good energy from all the dogs is evident. Since, in your situation, this aggression is happening several times a day, there must be times that you are there to witness it.  You must step in with your authority, before play turns to violence. Good solid obedience training helps you keep them all in control because you can say one word or give one hand signal and all of them will lay down or go to different parts of the room, house, or yard. Since this has one been happening over the last couple of weeks, you can jump in now and correct it before it gets any worse. Check around, there should be someone in your area that either teaches obedience, does training for shows, hunting, agility...that can help you. Please try the techniques above, leave me some feedback, and get back to me if you have any questions or problems. If you need further explanation, do not hesitate to ask me. I am here and can walk you through it as needed. Please let me know how it goes. Mary. I know little dogs can be just as tough as the big ones and understand your fear of one of them getting hurt. Thank you for writing.  Regards, Susan