Sudden Interdog Aggression

Hello. I apologize in advance for the length of this thread but since my problem is behavioral, I wanted to paint as clear a picture as possible. Plus, I've been told I'm wordy. I've been editing this for days now though so I just need to get it posted. First, some filler. We have 3 dogs, Bruiser, 5½ y.o. 8 lb fixed male chi/jack russell mix. Reyna, 3 y.o. 15 lb female chi mix. Vanilla P, 4 y.o. 14 lb female pom mix. The first 2, we've had since they were weaned. Vanilla P was about 1 when we rescued her, about 4 mo after getting Reyna. Bruiser is very passive, especially with the girls. He can be a mama's boy & I admit, I baby the snot out of him sometimes. Vanilla P is a typical pom, both +/- traits. She is always the first to growl & show her teeth, often. The other 2 are "our" dogs but she's definitely my boyfriends. My concern is about Reyna though. Her ad said chihuahua but she's obviously a mix. With what, we don't know but I like to think pit bull. Regardless, she is definitely a big dog in a little dogs body. She has always exhibited a kind of large breed puppy personality, that kind of clumsy, awkward, dopey, loveable rascal type of thing, if that makes sense. Oaf is a good description but she's not stupid. She's weirdly intense, though, although not in a mean or mad way. She just stares. Hard. She was also silent for almost the first 2 years, didn't even bark, but since has gotten more vocal in a growly/grumbly type of way. I don't know how relevant this may be but Reyna has always been orally focused, like, crazy focused. She mouths us all the time & licks compulsively, especially during times of high stress/anxiety. Most relevant though, she's always been incredibly patient & tolerant with Vanilla P, who can be incredibly ornery, pushy, almost like a bully, with endless amounts of energy that usually wears out the rest of us. That is, until recently. There have been a few dust ups over the years, as is to be expected, but nothing crazy or that didn't de-escalate quickly. More recently though, the last 6 mo to a year, Reyna has been less patient, acting grumpy more often & giving warning growls more frequently. She also has a habit of acting like shes security in our house. What I mean is any time we get mad at one of the other dogs or they get mad about something, she is right there, ready to "check" them. We never let her. She can also be quick to turn on one of them when she gets mad or frustrated. But she's never actually been really aggressive & saying her name was always enough to stop her from actually doing anything. A couple weeks ago, my boyfriend told me Reyna had attacked Bruiser while I was at work. I think what he said was after he picked him up, she bit his hand & then turned on Vanilla P. The way he described it, I couldn't reconcile that with our dog. That night, she gave a few warning growls but nothing too out of the ordinary. A couple days later though, Vanilla P was eating, Reyna walked in, Vanilla P growled. Typical. But this time Reyna growled back & then launched at Vanilla P. I had to break it up & my foot got bit or scratched in the process. They also didn't de-escalate when separated. After, every time Reyna would even see Vanilla P, she'd start growling, a lot. Fur up, the whole 9. At this point, I still thought it wasn't as serious as it was, we still had Reyna & Vanilla P loose together. Later the same day, they got into it again on our bed. I tried to break this one up & did but got bit by Reyna in the process. She was incredibly aggressive & tried for a long time to get back at Vanilla P. Since then, Reyna is unpredictable as to when she is triggered by Vanilla P. Sometimes it seems completely random, other times, it makes more sense. She was able to get at her another time & when she was pulled away, I would swear it wasn't my same dog. She was so vicious & out of control, it was like invasion of the body snatchers, dog version. I also noticed that she doesn't act like herself anymore. We couldn't get her to play & half the time she acted almost like she was brand new there. Now, when we're playing with the others, she shows up, as long as they make any noise, ready to check them. My "puppy" was gone. Reyna is always the first one to launch but Vanilla P is not innocent either. She is notorious for biting Reyna from behind when she is restricted & will growl & provoke Reyna to fight. But bottom line, she won't START the fight, Reyna does. Meaning, Vanilla P can be trusted to be loose, Reyna can't. I didn't think it was fair to keep her locked up somewhere separate so the way we've been doing it is she is always on a very short leash. Literally. There is no telling when she will be triggered but there is no more of them being around each other, loose, at all anymore. We are on edge when they get within a couple feet of each other. When she does get triggered, if she can't get at Vanilla P, she licks me, compulsively.  Its so weird to have a dog lick you while still growling. It is incredibly inconvenient to have to keep her on a leash, right next to me, constantly. Even when we're sleeping. The bad part is now that we're keeping them pretty much completely separated, for the most part, Reyna acts like her old self again. Although she still won't play with Bruiser. And even worse, I don't feel like I can completely trust her anymore. When she growls, I don't know if she's playing or serious & that goes with both my boyfriend & myself, not just the other dogs. I hate that. It hurts my heart that I feel that way. I had hoped in the beginning that it might be hormonal & so getting her fixed might help. Now, I don't think she's even in heat so it's unlikely to be that easy. I know it might still help but probably won't be an easy fix. I don't know what to do. We can't keep going like this, trying to keep them separate all the time. It won't work for much longer. Everyone is stressed out & on edge. I know that the way we react can be what triggers her further, her reacting to our anxiety, but I can't help but be nervous since she's so unpredictable now. Can anyone give me any advice or info to get my happy puppy back & get them back to at least tolerating each other?

Hello - and thank you.  That's a really good history. I think we need to stop thinking of this behaviour in terms of fault, innocence and guilt etc.   I know that in an ideal world, we have ideas that dogs 'should' be kind to one another, live nicely in human dwellings, be fussy but not too much, not argue with one another etc but dogs have none of thises concepts.   Dogs. like people, have highly evolved social patterns and don't necessarily know that you have an ideal default that doesn't involve them following their instincts, that competing or correcting one of their pack members is 'naughty.'   If you tell tgem off while this is going on (and I'm not saying that you have), they will often have no idea what they've done wrong because they have no moral 'wrong' attached to swearing at another dog.  At its worst (again, I know you're not doing this) I have known dogs that have associated barking at another dog with being hit.  So when they bark at another dog, you can see them looking terrified because they know what's coming.  Owners often tell me that these dogs feel 'guilty,' but no - they're just scared.  They don't have the concept that their natural way yo deal with an argument is wrong.   *sonething more useful coming*

I would reccommend putting all thoughts of 'fault' 'blame' and 'starting it' aside, and to concentrate on what's going on with the social dynamic and finding out what works.  Appropriate behavioural advice about the situation may be a good place to start, but unfortunately a lot of people call themselves 'behaviourists' and some give out very unconvincing advice in a very convincing way.  For this reason, ask your vet to reccommend someone with the appropriate qualifications; this may involve travelling or speaking to someone online.  Your vet may well have some suggestions themselves and sounds to be a great first port of call.  Meanwhile, it is important not to let the situation get worse - recognising and avoiding 'trigger' situstions sounds to be an excellent start and housing them separately for a while may be a reasonable idea.

Thank you so much. For reading that entire story, if nothing else. Everything I've read says to get a behaviorist, too. The problem there is we can't afford one. As far as the separation, it's not physical separation because we live in less than 900 Sq ft so we don't really have the room. To physically separate requires crating one & I just think it's unfair & even cruel to leave one locked up, alone, for any length of time. That feels like punishment & I don't want to punish them for following their instincts, I just want to let them know what behavior we expect. You don't have to like each other but u have to tolerate each other. I'm the alpha & this is how you behave in my pack. But I know that they have a different hierarchy & I'm a firm believer that they communicate just fine, only on a level beyond our perception. (Honestly, what i think is that Vanilla P is a s**t talker, and she finally said one thing too many & Reyna snapped. She'd had enough & wasn't taking it anymore.)  So far, our separation has literally been a 12 in leash. Reyna has to stay on it, all day. I have to hold the other end, all day. That is why it won't work for long. Plus I don't think it's necessarily fair to Reyna to never get to move around freely. So far, we've been trying distraction & praise for better behavior but it's not doing anything to change the initial reaction. We've talked about maybe we should just let them handle it the way they want to, fight it out, but I'm scared one of them will get hurt. Badly. Reyna can inflict almost nothing on Vanilla P because she has the armor of all her fur. Meanwhile, Reyna is practically bald & Vanilla P bites harder. But either of their eyes could be injured, etc. Plus, it might not end there. It is constant tension here though, unless we lock ourselves in different rooms. Reyna misses her dad & Vanilla P is never not at his side. Could this be something as simple as Reyna just turned 3 & now shes all grown up? What are the chances that this is still hormonal & she'll go back more or less to normal after her next heat?

Certainly it could be that the dynamic has changed as she has come into maturity, although maturity in most dogs is well below the age of 2 and this dynamic, from what I understand, is worsening rather than improving, so I'm not sure that it's realistic to dismiss it as teenage angst that will pass.  It may not be likely that it will miraculously resolve at the next heat - certainly it's not a good idea to base decisions on assuming that. Meanwhile, for various (good!) reasons, we are piling up options that you have dismissed for moving forward:  you have ruled out keeping her in a different room (space) or stopping her from moving around freely (space / wealfare); you have ruled out paying a behaviourist (money); keeping the status quo (it is scary and stressful).  A lot of vets might rule out neutering for behavioural reasons until you have seen a behaviourist, because it can sometimes have unintended effects, although for some dogs it proves helpful, particularly in the cade of eg lumps on ovaries.  Chemical neutering of entire animals can sometimes help, although I'm not sure where we are evidence-wise as to whether that predicts what would happen at neuter - it may not. My concern is, that you are running out of feasible options in the decision- making tree.   I wonder whether a vet exam to rule out factors such as pain might be helpful, although there are other behavioural reasons that might already explain what you are seeing.  If all of these possibilities get ruled out, it may be that local rehoming is a feasible option from a list of undesirable options?  It seems clear that one undesirable option needs to be chosen.  Your vet would be the best person to help you decide as they know the case best - I'm afraid that keeping the status quo does sound concerning / risky in the immediate term.  Wishing you all the best with this difficult decision.  'What evidence is there that -' is always a good question for you vet.