sick old piggy

Question
My 6yrs old guinea pig is very sick. He is moving very little and is unable to eat even though he tries. He has not defacated for atleast the past 12hrs but I did find a small quantity of fecal matter in its cage about 12hrs ago.He also seems to be experiencing some neck stiffness.

In my bid to rehydrate and re-energize my guinea pig I've feed it approximately 10 ml. of glucose water in the past few hours.

However, I suspect that maybe this will make matters worse but I live in Kathmandu, Nepal where Vets know very little about guinea pigs and are unable to help me.
       What should I do? Please help!  

Answer
Hi, I'm sorry to hear about your guinea pig.  Unfortunately i am not a vet and therefore won't be able to offer you much advice for a pig in such a condition, however i will do my best to advise you.
How long your guinea pig has been displaying these symptoms will dictate how currently life threatening the illness is.  If it has been within a matter of hours that your guinea has turned like this then i would worry that it may be fatal.  Sometimes pigs can develop infections or catch a virus that even prescription only medication won't cure.  I have had a pig that had meningitis and quickly developed symptoms like you describe, including the neck stiffness, which worries me.
If the symptoms have been gradual then it could be due to a number of illnesses.  Did you notice your guinea pig start with the inability to eat certain foods?  This can mean malocclusion which is when the teeth overgrow, misalign and cut in the mouth.
As we can not officially diagnose, the best you can do is keep things ticking over as best you can.  Syringing water is an important aid that you are already doing, keeping food going through the system is another.  Try liquidising fresh foods that he usually loves to eat and syringe feed him with it.  It can be detrimental to a guinea even only if there is no food going through them.
Keep him safe inside, in a quiet space.  A cool place may be more comfortable, as warm temperatures can worsen the effects of a virus.
I'm afraid i can not offer you any more, and i really hope that this is all you need to do in the hope of the illness passing.  You said there are no vets around who know guinea pigs, if you could find any vet they could at least advise on what to do in the case of any animal suddenly becoming ill.  You never know, they may be able to offer something to at least ease your guinea pig's discomfort.
I really hope this helps you - good luck and i hope your guinea gets out of it!