When do I know intros have failed?

[RattoPazzo]

I've been trying to introduce my oldy girl, Tamira, of two years to my two new girls, Sigma and Runa, who are 1.5. All of them have a pretty dominant character.
It as been slow, and for now I can have meating of just two of them because Sigma is very aggressive. I started with the carrier method with all three, but after 5 hours they were still figthing. So now I'm doing nutral territory with Tamira and Runa. This two understand eachother good but it's been 2 week and they still have not established a herarchy. I still can't put them in the same cage for more than 5 minutes before all hell brakes loose.
I'm beginning to fear that thay will never get along and I'm worried that I'm stressing my old rat, as she is the one that has to submit to the new ones.
On top of this, only after getting the new ones, I was told by my local rescue that many rats that come from the breeder I adopted the new rats from, have iperaggression problems that can only be solved by spay and "behaviural riabilitation". I don't think I have extreme cases of this but I did notice that the pinning is very prolonged and the stances are aggressive even after Tamira has submitted. The only positive is that Tami and Runa can eat from the same dish without attaccing eachother.
So, all that considerd, what do I do? Do I go on? Is there something else I can try?

 

[MinisterPumpkin]

Admittedly, all of my intros have been pretty easy, so may not be the best to give advice here. But I think you might be going a bit faster than this group of girls can handle. While there are general guidelines on the timing of the steps of an introduction, every rat is different and you'll need to go at the pace that's set by the girls involved.

I swear by the method described in SQ's thread on introductions. The same user has a reference thread with some more useful links on intros and other things. My last set of intros with older boys (one about 2.5 yrs, the other two estimated to be between 1-2 yrs) was as smooth as butter thanks to the gradual steps and the boys' general temperaments (admittedly the oldest boy was the most relaxed and welcoming rat I've ever met, so that helped a lot).

Since it sounds like things get pretty aggressive between your girls, I'd probably reset and start them off in separate but closely spaced housing for a bit -- swapping some items between them so they get accustomed to the scent of the others first. When that goes well, move on to neutral territory intros, and so on. Make sure you're not advancing to the next steps too quickly and let the girls take the time they need to get to know each other and feel safe/comfortable with one another.

I've only kept and fostered boys so far, so I can't say too much on the topic of spaying in particular, but I'd have a read through the links on the same reference thread if that's something you're looking into. I don't know if it's typically associated with aggression reduction, but I have heard that there are a number of other potential health benefits associated with spaying, so it'd definitely worth looking into for some of those reasons.

 

[RattoPazzo]

thenks, I'll for sure look at the thred you mentiond!
They are now living in the same room and shering the same free roam space (at different times). I did try the swapping bedding and living the cages near, but all I got was puffy and angry rats.

For now I'll continue with the nutral territory with just Tami and Runa and in a week or so I'll try to ad Sigma again mabye.

as for spaying, for now I really do not have the funds. I've had to go through 2 surgeris and 2 tc scans in 3 months. My oldy has now developed a strange mass on her neck so we'll still heve go go for a vet visit soon.

anyway, thanks again!