Karma has always been top dog, and would sometimes "attack" our rat terrier Jack when he'd do something to piss her off. This happened a few times a year. Well over the last 2 weeks, she has been doing it nearly every day. At first we thought it was pack related. But, just now, they were all playing in the back yard and she ripped into him. I put her inside and the other 3 stayed out. When we came in, the moment Jack entered the house she was at him again. I put her in the kennel for 30 minutes. My husband let her out and bam...again. My husband lost it and hit her. (NOT something I advocate) Let her go and she did it again. I'm fearing that we will have to get rid of her. She is such a sweetie. I don't understand this. They used to be the best of friends. Does anyone have any insight? We also just got the boxer pup about 2 months ago. She lets him do anything. NO aggression that we've seen. She is also fine with our germ shep/rott mix. Of course, she wouldn't have a chance against her.
Also, about 3 weeks ago, we had a neighbor dog (a small one) get into our yard and she rolled him in the same way she does Jack. We figured that was a territory issue. Now we are worried that it was the start of something more.
Well, I will risk getting grilled too.... but not because four dogs in the house is too many. Two dogs in the house is too many if they dogs are not properly trained and managed behaviorally.
Your opening sentence basically says what the root of the problem is -- your boxer has established itself as top dog over the terrier, and has learned that it can keep the other dog in check with aggression because you have allowed it in the past. And now another dog has been added to the mix to disrupt the pack dynamic further. And now one of the humans (who think they are at the top of the pack but probably aren't) have started using aggression to control the aggression?
I am sorry to say, but from the limited information given in the post, I do not think this is a "dog problem" at all. Dogs are pack animals, and when you own a pack you have to be able to communicate and lead the pack. This is where the problem lies -- the pack is lacking proper leadership.
Please start formal obedience training with all four dogs immediately. On a one-on-one basis, each dog needs to learn that you are in charge. Then, you obedience train them as a group.
Communication is essential to leadership -- obedience training alone will not cut it without two way communication. Obedience training will help, because it provides communication in one direction -- you command and the dog(s) obey. How do you get two-way communication when dogs can't talk? You have to be able to read them and know what they are thinking and what they are about to do -- so that you can either allow it or disallow it.
How? The dogs body language, eyes, position of the ears, hair on the back, what is he looking at, etc.... If the owner of two (or more) dogs is not experienced enough to see a situation developing and intervene to prevent it, then this type of situation is the unfortunate result.
I am afraid to say that it might be possible that you have exceeded the number of dogs you can effectively manage. The result is you either have to increase your capacity to effectively manage the dogs - which will take time and probably the assistance of a professional -- or give one or more up for adoption.
The absolute last thing that should happen in a dog-on-dog aggression scenario is for the human to interact with anger and hitting. While it is understandable that when this type of thing is going on and one is at the end of their rope they may think it might get the situation under control. However, it really just underscores to the dogs that their is no leadership or control present. If this continues, you may end up with a dog-on-human aggression problem.
Now, there is something I noticed that might be specific enough to help you get quick control of this situation. It sounds like the new pup is male, and the existing dogs are all female. Obviously, the new pup is unneutered, right? What about the females? Are they all spayed?
The reason I ask, is because what might be going on is that the new pup, by virtue of being male, naturally becomes the leader and the females are now fighting it out for second place to breed with the male. Making sure the entire pack is neutered/spayed may help, but training and leadership will still be required.
I have personally seen situations where un-spayed females have become aggressive towards other females, and the incidents occur most frequently when an un-neutered male is present.
