Sneezing?

Question
I have a girl rat (chee) i love her dearly.
She doesn't have a 'cagemate'. She sits on my shoulder whenever im not at school or work, she comes shopping and does everything with me.
I dont think she's lonely.
this morning she was continuously sneezing. its stopped now, but im still a bit worried.
she's in a spacious three leveled cage, using 'cat litter' recycled paper pellets. i only started using this a week or so ago, before hand i used saw dust.

she's a gorgeous little rat :D and i love her heaps, and just wana know if this is normal? cause id hate for anything to happen to her.

also, when they like make a 'grinding' noise with their teeth, does it mean they're happy?

thanks :D
hana

Answer
 The saw dust could have irritated her lungs and may have caused the sneezing.  Pine and cedar-based woods have phenols in them which can be harmful to rats, and even if the saw dust were from a different wood it can be dusty and irritate their lungs as well.  It may take a bit longer than a week for her to get back to normal.

 If it was just dry sneezing I wouldn't worry too much about it right now.  If the sneezing continues for more than a few more days, she begins to have wet sneezes, her lungs sound rattly or chirpy, she shows red discharge from her eyes or nose, or shows any other symptoms out of the ordinary you should take her to a vet for an exam.  She will probably be just fine, and if it is a slight respiratory infection a course of antibiotics will likely bring her right back up to good health.

 The grinding of their teeth is called bruxing, which rats do to wear their teeth down, but they also do it when they are happy =)

 I hope that helps you out, good luck with your rat!