It does sound as if your cavy is ill. A vet visit is for sure needed- glad to see you have this covered. It sounds like a respiratory illness.
Medication can fix this. Any animal when sick can act out of sorts and attack a cage mate. If it has stopped, don't remove him from his cage mate.
Pooping and eating it is normal. He's not actually eating poop- it looks similar but is actually ceacotrophs. This is usually consumed directly out of the anus.
Disgusting but normal. If you actually see your guinea pig eating this off of the ground it's abnormal. Most guinea pigs will eat this immediately upon excreting it.
Make sure your cavies are on a high quality diet. You are heading to the vet tomorrow. Tell the vet what food they are on.
Bring the package if you can. He or she can tell you if the vitamin levels are appropriate. I can tell you if you have fiesta or any kaytee product it is not nutritious and needs to be switched.
Good luck with your kiddo!
It is natural for them to eat their poop, its called copography. They do this for their digestive tract. But the only time they should be doing this is when the poop is soft, not when it is hard.
Maybe he is not getting enough nutrition. Always check the food bag expiration date, the vitamin C in the food is only good for up to three months and can fade when it is exposed to sunlight and air. But as for them fighting, seperate them, their could be territorialism going on and he may not be able to reach his food, water, or hay.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.