Quick Question About One of my Dogs Regarding Aggression

[gusishirt]

Hi there. I own two English Cocker Spaniel. They're both angels, love people and are super good family dogs. They are siblings, roughly one year apart (almost on the day). Both are females.

The older of the two (B) has always been very anxious. We're not sure why, but she's very alert and seems to never be able to relax. However, she does have her happy and excited moments. She loves fetch, loves to go outside and just play overall and loves cuddles and belly rubs too. She's really an amazing dog 99% of the time.

Lately, more around night time, around 8-9-10PM... she's been attacking her younger sister (J) if she gets too close. But not in a "you're in my personal space" or "you're annoying me" kind of way, but almost like she has a problem with her, eyeing her the entire time, refusing to play all of a sudden, not wanting to do anything but be super awkward and uneasy around everyone, like a flipped switch. They even play tug of war together with me and are usually fine. But once a night or every few nights she outright jumps at J, barking at her and showing her teeth, and it's been making J more scared to want to do anything as well, since she can read the vibe B is giving off when she's in that strange mood.

I'm wondering what this is? Why is she so uneasy? Why does she randomly attack her sister even though they're both totally find almost all the time?

Again, this isn't J bothering B or anything, it seems completely random.

 

[jesuslover1995]

@gusishirt I know you said B is older than J, so I wondered if B has also been living with you longer. If so, I could see it being a factor.

One other question I had is if they're actually making contact. Is it staying limited to teeth baring, growling, barking, that kind of thing, or is B actually going for the bite? That just wasn't quite clear to me, but it would paint two very different pictures. If there's no contact, B is very likely just putting on a very dramatic show to try and get J to go away and leave her alone. EDIT:: Just wanted to add that whether it's theatrics or not, the show is being put on due to discomfort, so it's still very worth looking into.

Sadly, it sounds to me like in some way, J IS bothering B. Very likely, it's not really J's fault, J is probably just as confused as you are. That is sort of why I wondered if you've had B around longer (if you have, is it by a significant margin?). Is there any specific routines that are happening on your end between 8-10PM that could be something B is maybe trying to defend? I also almost wonder if there's something outside that could be bothering her. Seems unlikely to me that it's something outside, but I hate to outright rule it out.

There are certainly things to be done that can help remedy this situation. I think the best way to start trying to do so is to figure out a root cause though. EDIT: I felt I should add that a behaviorist/trainer may be able to help more as well if need be.