Bleeding when urinating

Question
Hi Kat,
My guinea pig is sick.  He is squeaking when he urinates and there is blood in his urine.  I thought it was a standard urinary infection, but after a trip to the vets and nearly two weeks of antibiotics (baytril) he isn't any better. Although he is still eating, he's not eating as much and he is now loosing weight.  I am not sure what else to do.  His name it Tutu, because he has straight short hair at the front and long curly hair from the middle down.  That's in breeding for you!!  He is only 4 years old.  
I have 5 other piggies at the moment and tutu lives with his father who is perfectly healthy.  He has no other symptoms and I haven't changed his food or hay etc.
The only thing I have done differently is I have introduced a guinea pig salt lick. Both him and father love them, but they have been without one for about a month now.
Help please... any suggestions?

Answer
Hello Kay,

I would have Tutu checked for kidney or bladder stones. Sometimes UTIs can be stubborn, but since he's just been getting worse in spite of antibiotics, it's likely that may not be the problem. Stones can sometimes be treated with meds, but usually they require surgery. Good luck!

-kkat
http://www.geocities.com/abyssinianguineapigs