How and Why did my Guinea pig get so sick and die?

Question
I just absolutely adore guinea pigs!  I had six of them, but then today, my
three month old guinea pig ,Cheerio, suddenly got intensely ill and died
about an hour ago.  I am devastated, and i can't figure out how and why this
happened!  But I'd like to know the reason why so this won't happen to my
other guinea pigs.  Cheerio was acting just fine yesterday, but this morning,
he was suddenly sick.  He was just motionless in a corner, his coat was puffy,
and his eyes were teary and small.  He was not interested in eating or doing
anything.  I didn't think it was anything too severe, so i just went to work.  
But when i came back from work, he was laying on his side, moving jerkily,
and wheezing and gasping for breath.  I panicked and called the
veterenarian's emergency line but she did not pick up.  I thought he must be
suffocating so I picked up my baby and held him over a cup of steamed water
so he could inhale the steam.  I hoped this would open up his airway, but he
died in my hands twenty seconds afterwards.  I am very confused about what
caused this.  I love my guinea pigs so I take very good care of them so I don't
understand what went wrong, or what I could have done wrong.  Please let me
know what happened so this won't happen to my other babies!!

Answer
Hi Karen, i'm sorry to hear about the loss of your guinea pig.  These times really are the worst and i sympathize with you at this time as i lost one of my boys two days ago.
Guinea pigs are very naturally very good at hiding illness and can carry bugs of all sorts before they make an appearance.  I find that cases such as these, the deaths have been due to viruses.  Many are unexplainable even by vets and as such can only be determined by autopsy.  Guinea pigs are also weak at suffering from respiratory infections and anything affecting the airways can pretty much go downhill rather fast.  When a pig is fluffed up in a corner of his cage and looking depressed it is always a bad sign that things are wrong.  Even quick action at this time isn't guaranteed success so i would hate you to  beat yourself up over it.  You did what you could and i thought the steam was an excellent thought on your part.  I'm just sorry that you had to experience such a horrible way for your pig to go.
I would suggest you give your guineas a good health check and maybe get your vet to check their breathing is alright.  Other than this there isn't much you can do other than put it down to an infection your pig couldn't fight, as like i said, viruses can be nasty to guinea pigs.
I hope this helps you.
Kind regards
Becky
www.cavycapers.com