Fighting

Question
Hello,
I have two male pigs who have lived together for a number of months.
recently one of them suffered from a a fungal infection. Whilst i was treating him i separated them both. after about six days I reintroduced them. This did not go well and both were chattering their teeth. I left it for another couple of days before trying again, this time I put them in a new run to avoid a territory battle and I also applied vix to their noses to disguise the smell. All seemed to be going well so after a while I left them for a short time. On my return I could see that they had been fighting and the older one of the two had lost fur and his face was bleeding. I split them up and have not put them together since.

I know that Guinea Pigs are sociable creatures and would really like to keep them together. Do you have any other suggestions please

Answer
In general they are social animals, but they are herding animals. In any herd there is always an alpha male who maintains the position of the leadership and also holds the breeding rights to the females.

Horses, cattle, wolves, lions, hippos, chickens,  just to name a few, have that hard wired herding instinct. Guinea pigs are the same way. As the male babies come along they are allowed to stay as long as the don't challenge the leader. When they start to reach puberty they begin doing just that. Once they do that a fight begins and the winner maintains control while the loser is banished from the herd. If it's the older male who has been king he will be kicked out and will die. If the younger male is defeated he will leave to find his own harem.

When boars are housed together they will get along until there is a separation. Once separated a territorial fight will begin when they're put back together. They have no memory of liking one another. They're simply acting on instinct and hormones. The guy left in the cage has assumed the position of leadership and will fight to keep it.

I use my senior boars as 'nannies' to the baby boys that are weaned. They get along beautifully for awhile, but there comes a point when the young ones start showing their muscle and try to push Dad around.  At that point the party stops and the boys have to be separated.

I've had brothers that lived happily together, but taking one of them out of the cage when we traveled for a few days to a show caused that same behavior when they came home. It's animal instinct and there isn't much we can do to change that to fit our needs.

When you see hair pulled and bloodshed there is serious aggression and one or both of them will be injured, badly. At this point they are best left apart. To try to make them come to peaceful terms at this point is only going to cause more combat.