My Guinea Pig wont eat or drink, help!

Question
So I recently went away for a weekend and like I always do before going away, I make sure my guinea pig has plenty of food and water.  His/her (not sure of the gender) bowl was filled to the top with lettuce and food and I had just given him/her fresh water.  Before we left, everything was fine.  He was eating normally and drinking normally.  However, after I returned from my weekend away, I noticed that his food and water had gone completely untouched for 2 whole days!  This is completely unusual for him/her because my piggy eats a lot!  He also isn't making any noises and he just sits around in his/her igloo all day.  I'm not sure if this matters or not either but ever since we got him he has tended to shed a lot and sometimes is prone to dandruff.  I'm pretty sure he/she doesn't have mites though because I have never seen a bald patch on him or anything.  Also, I give him bathes about every month.  What could possibly be wrong with him?  Are there any home remedies I could possibly try?  Please help!

Answer
Leaving a pig unattended, even with food or water, is a real leap of faith. Whatever happened to him, not drinking for two days is very serious. My first thought was that he may have suffered from heat exposure but I don't think it's been that hot in NJ.

Sitting in his igloo and not taking in any food or water is a sign of something serious. I think a trip to the vet is in order.

As for the shedding, that's not a sign of mites. Also mites don't necessarily have to show a bald spot to be present. Poor coat condition is a sign of something other than mites. Some breeds, like Teddies, will get dandruff at times but this honestly sounds like something more.

If he's an old pig (over four years of age) he may be showing signs of old age. They begin to lose weight, coat condition is poor and they just slow down. This is usually a sign of coming departure.

I really think it would be in his best interest to make a trip to the vet to find out what the problem is. And please keep in touch and let me know.