Ratties Can rats pass on URIs to guinea pigs?

That's a good question!

Gosh I'm kinda freaking out right now b/c I don't want to take them to the vet...will if I have to though....my piggies are sneezing occasionally, 3-5 times a day. Is that OK? Is it normal?

I don't know. Keep a close eye out for discharge and lots of sneezing.

There's no discharge or anything, just sneezing like 3-5 times a day. I'm worried D:

When my cat had a suspected URI (turned out to be the feline herpes virus), I asked the vet this very same question. She said she was taught in school that problems of that type aren't supposed to move between species, but that she's seen some odd things and would recommend keeping the cat away from the pigs. Given that rats are a closer species, I'd definitely not want to take any chances.

Who is sneezing? The rat or the pigs? At any rate, please take the rat to the vet. It's possible he has myco--a very common respiratory infection in rats. He will need antibiotics.

From what I learned in my research you should never house rats and Piggy's in the same room as the rats can give the piggys URIs. Don't quote me on that, its what I read while researching. I've got my piggy and my rats desperate so as not to risk it.

my rats and gp have been housed in same room since I got the gp's
resp in rats is usually caused by the Myco which they already have and tho some subscribe to it being catching I find its more their environment that causes issues and flare ups
URI are usually a secondary infection if myco hasnt been treated properly and quickly so if you just have myco resp I wouldnt think this could be passed on (unless its known for GP to have myco in their system too)

Bacterial infections are contagious but viruses are not between different species with a few exceptions (like the swine flu) that crossed species.