Blood,snuffle and sneeze

Question
Hello!!

One of mu guinea pigs got blood coming out from his nose, but not much.
It was not as red as real blood does.
It was just like blood mixed with water.
There's no more but, just for now

He also snuffles and sneezes as I can see.
Most of my guinea pigs do snuffle sometimes, may take 1-3 days to be covered.
I really have no idea what is happening with this one.
If it's because the weather suddenly changed?
Or he might get cold?
How could I treat him properly???

Thanks for your answer

PS. My boy is nearly 6 month old.

Answer
Hello,
If your guinea pig has been sniffling, sneezing and has a runny nose then these are symptoms of upper respiratory tract disease.
Other signs include blood stained crusts around the nose (like the blood from his nose), discharge from the eyes, and some difficulty breathing.
This is often caused by an allergy of some sort, bacterial infection, an irritation from inhalation of smoke, or if you use pine/ceder bedding then the fumes/odours from these can cause irritation of the eyes, throat, nose and lungs.
If you need to change your bedding then i suggest woodshavings or hay. If your guinea pig has an upper respiratory tract disease then I suggest you go to your local vets immediately so that they can help your guinea pig and suggest what to do next
I hope this helps
Aleksandra