please help...sick guinea pig

Question
hello, i have four guinea pigs, two males and two females.  One male and one female are the mother and father of the other two.  I got them from my boss about two weeks ago.  Everything has been fine up untill about two days ago.  My girlfriend that lives with me takes them out of the cage everyday so they get a change and are around us so they can get used to us being around.  At first she took all out at once and lately she has been taking two out at a time, she alternates the days so every other day they come out.  My question is today when i came home from work I asked her if she took them out at all today and she said no.  I asked if she could take them out so they can play and when she grabbed the mother she found that she is very very skinny and her eyes are only half open.  When she stands still she will fall over sometimes for no reason.  When she walks she struggles and wobbels alot.  Also the other guinea pigs bite at her.  I seperated her from the others to see how she would react if I gave her some food and water and the others obviously got mad at me and tried very hard to get to her.  They were getting very aggresive untill about five min. of being back with her but they cont. to bite at her and pull on her hair.  One question is, is this normal and what does it mean.  The other question is what can I do for her and how can I help her.  I don't have the money to take her to the vet. and I really don't want her to die because I have become attached to her a little.  One thing I forgot to mention is when I seperated her from the others and gave her food and water she wouldn't eat but she would drink water very slowly and just a little bit.  I am afraid the others aren't letting her eat.  Also when I got them they were eating cat food and now I have them eating guinea pig food.  Can you please send back asap as I am in need of dire help.

Thank you very much for your time to read and answer,
Jeremy

Answer
Hi Jeremy

I am so sorry for the delay in replying, I have been away for the weekend.

It certainly is not normal for the other pigs to become aggressive with the mother and you should separate them now and keep the mother in a warm place.

The symptoms she is showing are really signs of general ill health. You will need to start syringe feeding her with water and food, and please make sure you give her food high in vitamin c and calcium and vitamin d. After 24 hours, please let me know if there is any improvement in her condition.

Andy