No. Director T.F. Mou has recently debunked it in a biographical documentary currently in production.
The cat was covered in colored honey and then thrown into the rat pit, where the rats simply licked the honey off the cat. If one has the stomach to look closely at the scene, you'll see that the rats never bite the cat, the blood has the consistency and color of dyed honey, the cat never develops any realistic looking flesh wounds and the cat never fully stops moving.
Mou has simply shied away from the topic in the past because he believes it hypocritical to be upset over a cat when the point of his film is to show the desecration of humanity by other humans.