With its large size and massive jaws and teeth, C. spelea was a formidable, "puma-like" predator, and in addition to smaller lemurids, it may have eaten some of the big, now extinct subfossil lemurs that would have been too large for C. ferox. No subfossil evidence has been found to definitively show that lemurs were its prey; this assumption is based on the diet of the smaller, extant species of fossa. Other possible prey include tenrecs, smaller euplerids, and even young Malagasy hippopotamuses. Its extinction may have changed predation dynamics on Madagascar.