Conflict between sows

[HGee]

Hi everyone,
I have 4 piggies - 3 females and a neutered boar . We were left with our male (4 yrs old) and female (3 yrs old) as we lost a female piggy at Christmas. In April we introduced an 8 week old female to the group. There were no issues (I have had Guinea Pigs all my life and introduced individuals several times during my adult life) and all was normal. We then acquired a 4th piggy in May, another girl 9 wks old, and introduced her to the group. Again no issues until the past few weeks were the girl we got in April jabs and chases the younger one. They are in a huge indoor enclosure which has several food bowls, water bowls and hay racks. They have plenty of tunnels and hidies, but the April girl will leave her hidie at one end, go the other end of the enclosure and force the other out of her resting place and chase her. Over the past two weeks she has started to “hiss” - has anyone else ever experienced this? We never have. She forces air out of her mouth at the other pig before charging at her causing her to alarm squeal and flee. The other girl has started making alarmed noises every time this problem one is in the vicinity, will sometimes stand her ground by not moving and making loud alarm noises at her, but the other will just hiss and run at her . Should we take the “problem” piggy out of the group? I don’t want to split up our original two so splitting the group in half isn’t an option.
Thank you in advance.

 

[My Piggies]

Hi,

How long exactly has the female been chasing the other? It's possible that she may be in heat. This sounds like normal dominance behavior to me. As long as they aren't drawing blood, I wouldn't worry too much, but if it has been going on for weeks then there may be a compatibility issue.
@Piggies&buns
Do you have multiple of everything (water bottles, food bowls, hay areas, at least one hide per piggy)?
I'd also only have hides with two entrances until they settle down so they can't corner each other.
How big is your cage exactly?
Hope this helps, someone with more experience will be along shortly.

 

[Piggies&buns]

It sounds like you have a teenage sow pushing her dominance.
If it is happening only when she is in season, then it may be just that.
However, if the behaviour is more constant and sustained, then it may be that the bond there is not a good one.

The squealing from the other piggy sounds like it may just be submission squealing which sounds dramatic to us but is a good sign in that she is accepting her lower ranking position and not trying to fight back

Keep an eye on all their weights but particularly the little one. Any bullying can show up as weight loss.

The guides below explain further

Sows: Behaviour and female health problems (including ovarian cysts)
Dominance Behaviours In Guinea Pigs
Bonds In Trouble
Moody Guinea Pigs: Depression, Bullying, Aggression, Stress, Fear and Antisocial Behaviour