Guinea pig black, crusty nose and mouth

Question
Hi, I was hoping you might be able to help. My guinea pig has developed what looks like a dark crusty patch under her nose and around her lips. It looks like she has eaten poop and it has dried on her fur but it is not easy to wash off. Have tried gently washing her nose and mouth with water, but she doesn't like it and squeaks a lot.She has only had this for the past two days. Not sure how to treat it. She may have eaten a carrot with a spot of mould on it.Thanks, Sharon

Answer
This is a tough one without seeing a picture. She may have indeed eaten some poo and left the telltale sign behind. Try using some baby oil, or if you don't have that just use cooking oil to soften it to see if that will help wash it off. Leave it on overnight then use a soft rag with some soap and water. Hopefully that will help clean it off.

If you're able, can you attach a picture so I can get a better idea of what you're seeing?