Guinea pigs can have dark orange urine normally due to pigments they ingest from their food. True blood in the urine can occur commonly as well and cause pink to red urine. Blood in the urine may be due to an infection or urinary stones in the bladder or kidneys. If there is any concern, I recommend an examination and collecting a urine sample for testing to see if there is blood present.
Hairloss on the face can also be from several causes such as trauma, parasites, or infection. An examination and some simple in- hospital tests can help decide the best treatment.
We would be happy to see your guinea pig and make sure he is happy and well. Please call us to schedule an appointment.