Take your pet to the vet RIGHT AWAY! After having Apollo for about a month and a half, I came home from work one night and noticed a little bit more than just a bit of green around 1 nostril, his faces was COVERED in green crunchies, as though he had been sneezing all day. I also noticed the same green crusties all over his paws, he was trying to wipe his poor little piggy nose, but it wasn't enough to clean his whole face - and I remembered I had seen him washing his face a lot in the days before that.
Well, we took him to the vet ASAP, and she told us he was VERY SICK and that his chances of surviving weren't very good
We were given medicine and a syringe, and we did everything we could for him but he still died after being on meds for a week
That was the first and only time a piggy has gotten sick and died on me.
a few months after Apollo died I was ready for a new piggy, and after THOROUGHLY cleaning his cage, completely replacing water bottle, toys, and food dish, I brought home Cupcake. 2 weeks later I came home from work, and once again I had to deal with a piggy with a bit of a crunchy nose. I just couldn't take it, he was much too cute and sweet of a piggy to die on me. I sat there holding him and crying until my boyfriend got home (he left work early - IT'S THAT SERIOUS to me...) and we took Cupcake to the vet asap - fortunatly we got him there in time, and he wasn't as sick as Apollo was when we took him in - we got medicine and syringe, and after a week of medicine he was all better. We were still watching him and didn't let him play with Dante for another MONTH after recovering.
The only thing I advise you check before you can visit the vet, is his oinker working? Apollo made a raspy "arf" sound, while Cupcake always made a very crisp "OOOIIINK!" noise. Their lungs don't work very well when they're sick, so do whatever you need to to check if his lungs are ok right now, when I want to check Cupcake's oinker I open the veggie crisper in the fridge and he knows he's getting a treat if he sings for me.