Is it normale that my guinea pig growls at his cagemate?

Question
Hello I'm alison
I would really like to now if I should be concerned about my male guinea pig ((Gizmo)becase I sometimes catch him growling at his cage mate (Neo) I m scared one day it won't be just a growl that it might be a bite!
If you have any advise I would be more than gratful thank you!!!
And also how often do I need to bath them( there long haired ) but I now that you should  brush them almost every day!

Answer
a purr is common and normal teeth chattering is the threatening noise, by you saying growling to me it all sounds like normal dominence behaviour, as long as they are not biting one another (which they would have done by now) then i doubt you have anything to worry about

all the best please comtatc me again if you have any further questions or problems.