Wobbly head

Question
Hi,
I think a bit of background may help... I live in Singapore which is very hot, so my two house guinea pigs live indoors in a cool airconditioned room. When the second one got to around 9mths they started fighting, so a very good friend took the younger one to keep her pig company as she had just lost one of hers. That was about 3mths ago, and all had being going very well.
However, she doesn't use airconditioning, and Sid lost a bit of weight to start with but put it back on again and seemed happy enough. My friend called today very upset as he was lethargic etc and could I take him for the weekend to see if it is a heat problem.
He is here now, in a room without aircon as I didn't feel that it was fair of him to be cool for a couple of days and then back into the heat. I have been watching him and he seems to have perked up a bit, has just had his greens for tea and is tucking in. What I have noticed is that his head sort of wobbles from side to side. Almost like he is slowly saying no. It is constant, but doesn't seem to stop him eating.
Do you have any ideas what it might be? Thanks in advance for your help, and sorry this is a bit long!!!!

Answer
Hello,
I think you should let your vet know your worries but for now I will give you my advice. I think you should keep your guinea and maybe let your friend but a new pet because you have a cooler and better enviroment for your guinea. Compare Sid to your other guinea and see if its head wobbles aswell. I don't really know what his wobbly head is but maybe he has something wrong with his head, maybe his muscles aren't working aswell or maybe it just takes him time to adjust to a new enviroment.
Best wishes
Aleksandra