Lice are a very common disease in not only
guinea pigs but most other rodents which are kept around the
house as pets. Due to their very small size lice can be difficult
to see without the aid of a microscope.
The lice parasites actually bite small holes in the skin
of the guinea pigs which causes minute amounts of bodily fluids
to expell through these holes. The lice survive by consuming
this fluid while they are living on the guinea pig. Depending
on the degree of infestation you may or may not see this blood
on the surface of your guinea pig.
Veterinarian assitance is recommended if you suspect a lice
infestation because they can not only confirm the diagnosis
by either provide you with or recommend a shampoo which can
eliminate the lice problem. After you have eliviated the infestation
be sure to thoroughly clean the guinea pigs cage. Failure
to do so can leave lice in the enclosure which can attach
back to the guinea pig once it is placed back in its cage.