Guinea Pig - Ill Health

Question
Hi, I have a 3 year old male,not neutered who lives on his own. He has always been active, and greets me when I go near his hutch.
 For the last 3 days he has been acting strange. Today is his worse day. His symptoms are small amount of nasal discharge, fast breathing rate. He has gone off his food today, and hasn't drunk much  either. He isn't defecating or urinating much. His stomach feels a little bloated, and hisfeet are hot to touch. He hasn't been squeaking or talking  when I have been stroking him.When I got him out of the hutch today,he kept moving forwards and backwards, like he couldnt walk. If I roll him on his back on my lap, he just stays there. Its like he has a central nervous problem. I am keeping him indoors for the next few days, and syringe feeding him water & vitamins, and antibiotics (baytil) He isn't eating his dry mix and isn't interested in veg either. Any help is appreciated, Many thanks,  

Answer
Hi Chloe

Firstly, sorry to hear your piggy is sick and I am sorry for the delay in responding, I have been working.

Make sure you give him plenty of vitamin c if possible, but other than that, you will just have to wait and see if the antibiotics work. The symptoms you describe could be a number of ailments. If anything changes please let me know.

Andy