Gpiggy not drinking

Question
QUESTION: Hello, I have a two year old Guinea Pig named Mindy.  She seemed more quiet and stayed in her bed the last two days.  Then yesterday she would not drink at all, and she ate minimally.  I gave her some lettuce, tomato, blueberries, carrots, but she just nibbled a small amount.
Today I brought her to my vet first thing.  He found nothing wrong. No tumors, no obstructions, teeth are fine, no temperature. He gave her a Vit C  injection and critical care mix.  
I wish he had found something bothering her.  Nothing has changed in her environment and I have an AC running at 74 temp.  I'm totally at a loss of what is wrong.
Any suggestions?
Thanks for your help.

ANSWER: In most cases a lack of interest in food or water is a red flag warning. But since your vet was unable to find anything particularly wrong I'm as confused as you are. She's in a comfortable environment so it's not the heat that's the cause.  

As long as she's taking even small amounts of veggies she's getting the liquid she needs from that. Give her the Critical Care as that will maintain her nutritional needs. Hopefully this is just a fleeting thing and she will pop out of it.

Please keep me posted as to how she's doing. Let's hope it's just the "lazy days of summer" that are making her listless.  

I wish I had something more absolute to offer, but I just can't think of anything that might be causing this.

---------- FOLLOW-UP ----------

QUESTION: Thank you for getting back to me so fast.  I'm glad that it's puzzling to an expert too!!  Mindy HATES the critical care mix.  I've figured out a plan to get her to eat it though. I put it on red leaf lettuce and she eats it!!  She still has not touched her food mix or water bottle.  Again, nothing has changed.  I had bought her a new water bottle, same type different color (?) so yesterday I put her old one back again, but she would not drink. We have been cleaning out the basement, but that has not effected the area where she lives.  
Do you recommend the Oxbow Vit C tablets for her to chew?
I usually give her fresh oranges and tomatoes for Vit C.

Thanks again for your concern.
Heidi

Answer
If he will eat them the tablets certainly won't hurt him. But Vit C is a widely misunderstood mineral. Our bodies need a constant supply to keep healthy. Some animals make their own Vit C while others, like cavies, do not.  They have to have it supplemented in their diets.

Daily supplements keep them healthy and strengthen their immune systems. It does the same for us. It helps us ward off the common cold, prevent scurvy by keeping our bones strong, and keeps our immunity healthy. When we get sick taking massive doses of it does nothing more than irritate the lining of the stomach and has the potential to cause ulcers.

Giving mega vitamins to a sick person or animal is counterproductive. They can't handle the overdose and the effect is often disastrous. So in that respect giving it to Mindy now may not have the effect that you hope.  

In other words vitamins do not cure anything. They help to prevent. You might try putting a little Gatorade in her water bottle and see if that encourages her to drink. Also when you mix the Critical Care, taste it. Make sure it doesn't have a bizarre taste that would keep her from trying it. Don't be afraid, there's nothing in it that is harmful to humans. Even their pellets are just compressed alfalfa.

It still doesn't really sound like she's sick, she's just off her feed.