Previously bonded pigs not getting along after one had surgery

Question
I'm sorry I have a very long question but I really need some help with the problem! I'm very upset with what's happening.

I have one 2 years old male (desexed) and one 1 years old female pig.

The male pig, Ben:
he was living with another male before and he was always the submissive one, he once in a while challenges his buddy but he usually knows he is not the boss. Unfortunately his buddy died of a heart attack so we decided to desex him and find him a girl.

The female pig, Mallow:
We adopted her through a shelter, before making the decision we had both pigs put together in a play pen and they appears to be getting along well. The first day mallow arrived home, Ben did alot of mounting, made some 'deep purring' noise and 'swings his butt'. No mounting behaviour was seen since then and Ben only occasionally show dominance behaviour such as butt dragging. I have never seen Mallow exhibiting any signs of dominance/aggressive behaviour, no matter what Ben is doing. If she's chased she will sometimes run away, but most of the time she stays at her spot looking calm. However, when it comes to food, Mallow is very greedy and always tries to eat the piece Ben is eating, Ben will leave his food right away and picks another piece so they dont fight over the same piece. I dont know if this makes him 'less of a boss'? They dont fight over anything because they have their own hideout, and the cage is pretty big. They pretty much do everything together and sometimes they snuggle up and sleep together.

The issue:
One month later Ben was taken to surgery because he has abscess. One from the castration and one the vet suspect was caused by a bite. I am very surprised by the idea that mallow had bitten him. It has never come to my notice that they had any 'argument' at all. But I cannot be sure of that because I am not at home 24/7 to monitor their behaviour.

After the surgery I separated the C&C cage into half. They had been living separately almost two weeks by now. 3 days after the surgery (Ben was still taking medicine) I let them out together and be free range in my room while I cleaned the cage. They appeared fine at first but not long afterwards they fought over a hideout and things went downhill ever since. They immediately became aggressive at each other, involving alot of teeth chattering and butt nudging. Ben had all his hair stood up and Mallow was snorting, stomping her feet and nips at Ben which occ. pulls out some hair. I have never seen her behave like this.
Ben runs away and squeaks when she nips at him but when she cools down a bit he finds her again and sniff her butt or 'swings his butt'/ teeth chatter, this will then arouse mallow again and she becomes very aggressive if he does these.

There hadnt been a full blown fight (if there will be!) because I interrupt their interaction once Mallow starts to nip. I thought I should have given them more time but since Ben is still in recovery I would not want more trauma to the already stressed pig

A week has passed and things had not improved a bit. I tried putting them together with a bowl of veggie to share. They ignore each other and eat at first, but when they are done with it they start to make those noisy squeaky 'argument' noise again and teeth chatter.  And since the 'fight over hideout' incident Mallow had been chewing the fence that separates them ALOT. She pulls on it very hard as if she wants to go to Ben's side very bad, Ben usually ignore her or do some 'purring' and butt swinging in response. She did not do this before and she has a wooden bridge to do her normal chewing.

I dont know what I should do to make them as happy as before. I'm very upset because I felt it was perhaps a mistake separating them.

Do you have any clue why these previously bonded pigs dont get along anymore? Should I bath them together once Ben is healed (to wash away their scent?)?.

I'm very sorry for the 'essay like' question. Your help is very much appreciated! Thanks alot!

Answer

subglottal abscess First of all Abby, don't apologize for the lengthy letter. I don't mind at all. What you're describing isn't unusual.  Many times animals that have gotten along suddenly change behavior after being separated for awhile.

We tend to think of sows as being the mild mannered ones. But just like humans they actually rule the household. Some of Mallow's behavior sounds like PMS (piggy menstrual syndrome) and may come from being in heat. The girls come into estrus on an irregular basis, some every two weeks some a little less often. They can and do become aggressive during that time.

The butt dragging and swaying you describe is what we call rumblestrutting. It's the cavy equivalent of flexing muscles to show off. Generally that's seen when the male is trying to convince the female he 'wants her.'  When it's coupled with teeth chattering and hair standing on the back that's aggression.  

Abscesses are fairly common in guinea pigs and are usually found around the throat and sides of the cheeks. It's almost always staph that causes it and starts from a break in the skin. A pig will sometimes scratch themselves with dirty toenails and an abscess forms. They can also occur from a bite and are usually located on the back or butt as the animal tries to retreat. I've attached a picture of a Kindergarten pig that came to my house for treatment of a typical subglottal abcess. Fortunately they respond quickly and easily to treatment.

I think I would remove both of the hideouts as that seems to be causing territorial disputes. In most cases they will work it out themselves, but if it's becoming violent you may have to keep them separated. I also think bathing both of them is a good idea. That might help remove any odors from the vet's office.

It still sounds to me that Mallow is exhibiting signs of "take me" to Ben. Sows will even mount one another during these times. It's a hormonal drive that they cannot help. When a boar is first introduced to a breeding pen he will purr, rumblestrut, sniff and try to get frisky. If the sow is not ready she will (and I've seen this hundreds of times) turn around,arch her back and shoot a stream or urine directly into his face. She never misses and it cools his jets in a flash. Like most species the girls choose the time!

Castration doesn't totally remove the drive to reproduce. Ben may still respond to Mallow as if he were still intact. In most cases just leaving them to work it out does the trick, but if you have constant teeth chattering and and hair pulling you may need to keep them apart. I've found that making gradual introductions doesn't seem to work. As soon as the cage is opened the territorial issues start all over again.

There's one more thing you might try. I have done this many times when a sow died giving birth and I needed to foster the babies. Animals function by smells, and a new mother knows the smell of her own babies.

Dab a little bit of Vick's Vapor Rub on Ben's nose. It masks the smell of hormones that makes him chase her. You can also put some on her nose and on her rear. He will be confused by the odor and leave her along. If they don't have that product in Australia you can use any kind of ointment that has a camphor smell. It distorts the normal sensory smells that drives them.

Hopefully this will give you a little peace in the household again. It just goes to show you that the women really do rule the world. We can make life miserable for the men around us if they don't do it our way.

Good luck to you.  Please do let me now how this works out.