red urine from my daughters guinea pig

Question
My daughter's guinea pig had red urine today.  The guinea pig looks perfectly healthy but my daughter is very concerned.  We normally feed it either timothy and regular pellets for guinea pigs, carrot tops (greens), celery and lettuce.

The day after she cleaned the cage there was a horrible smell.  Not normal.  Can you shed any light on this?

Answer
I would recommend having her checked for a reproductive cancer, ovarian cancer or infection  ovarian cysts, bleeding is unfortunately a normal symptom for all of these. I had a guinea pig named Cappuccino and unfortunately she had vaginal bleeding as well, it turned out to be ovarian cancer. And Rhinestone also had vaginal bleeding but it wasn't gooey and was more like pee. She ended up having to be put down because of it. I had the vet check post-death and it was confirmed as bladder cancer. I am afraid I checked a lot of websites and the only other explanation is that a piece of hay got stuck in her privates and left a cut. You need to take her to the vet ASAP or it could get worse. Also try to make sure it is an exotic pets vet with experience in the area of guinea pigs. Another possible but unlikely cause is she may have worms, also serious.
Hope this helps, and give the piggy a hug for me!

Thanks for asking!
-Nicky