I am sorry Coco is having trouble. It sounds like she has interstitial cystitis. That is a bladder infection with no bacteria seen upon exam. She experiences a burning sensation when she voids.
Esteemed authorities believe this is caused by eating dry food:
Give her 4 drops of cranberry juice by dropper, every day for ten days to lower the PH of her urine and stop the burning.
Up her fluids by giving her tuna water drained from the can.
Please let me know how she is doing.
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