fighting or not?

Question
We bought 2 guinea pigs and at first they seemed to get along just fine.  Today, just a few days over 2 weeks that we've had them, I noticed the smaller of the 2 had a wound on his upper back just behind his neck.  So, I did a make shift separation in the cage but is this just tough playing?  Are there any specific noises they make when they fight?  They almost sound like between a purr and a growl?  After separating them, they seemed to want to see each other?  How can I help them get along?

Answer
Hi Corine

Fighting between 2 piggies is actually pretty scarey and savage so if they arent literally tearing shreds off each other then it was probably the routine that 2 males go through to decide which is boss.

Please keep a close eye on them though and let me know any developments.

Andy