Beyond the Gut: Novel and Expanded Fiber Exposure Pathways in Small Wild Felids and Implications for Domestic Cat Diets

AbstractDietary fiber in small wild felids has likely been underrecognized and underestimated largely due to scat-based analysis that undercounts soluble and fermentable fractions and prey-based diet modeling with incomplete accounting of transient or compartmentalized plant loads. Perceived pathways and potential benefits of dietary fiber can be further obscured by downstream interpretations of the term obligate carnivore that imply negligible plant intake or benefit. Direct consumption of grasses, along with indirect sources such as prey stomach and intestinal contents with partially fermented material and microbes, insect chitin, environmental debris, and avian crop contents, all contribute to fiber exposure. This paper introduces a newly proposed pathway, the ingestion of rodent cheek pouch contents, which may represent a substantial but previously unrecognized source. Taken together, these routes suggest that small wild felids may plausibly encounter ~5–10% dietary fiber on a dry matter (DM) basis, a context-dependent range intended to correct for overlooked pathways and underestimation in scat-based methods and prey-based diet reconstruction approaches. On an as fed basis, including indigestible components such as fur, feathers, and bone fragments, total intake volume may approach ~30%. Recognizing these multiple pathways broadens our understanding of fiber exposure and may inform the integration of functionally equivalent dietary fiber into feline nutrition science and prey-based diet modeling in the domestic cat (Felis catus). Insoluble fiber may serve as a surrogate for the mechanical role of fur and feathers, providing bulk that supports stool formation and promotes gastrointestinal motility, and fermentable fractions support the gut microbiota and the production of short-chain fatty acids (SCFAs).This is a preprint and has not been peer reviewed. It may be updated in subsequent Zenodo versions. If accepted for peer review/publication, a revised manuscript may differ from this version.