"Is there any animal sources of fiber?"
There are no animal sources for fiber. Fiber is proprietary to plant based foods. I've looked at countless nutritional charts, from various research facilities, from the various college research facilities, to medical research facilities, and various government research facilities, and from various countries. Not one has ever listed finding fiber in animal based sources.
While it is possible by the way to eat a diet of nothing but meat, it will be missing vitamin C, unless you know where and how to acquire it. It can be done, but it's also dangerous. You NEED plant based foods in your diet. We are omnivores, not carnivores or herbivores. Animal based foods should on average make up not more than twenty percent, the other eighty, and more realistic amount of ninety percent., should be plant based foods.