Again, you seem to be mistaken. In game lore points to stories of werebears in Skyrim. Whether or not they exist, stories of them do. Both of these are absent in Skyrim's populace.
The book "On Lycanthropy," which first appeared in Daggerfall, brings up the existence of werebears in Skyrim. In fact, werebears are the first type of lycanthrope mentioned.
They are confirmed to exist in Infernal City, which again, does appear to be canon considering events in it are referred to in Skyrim, but their first mention is in game lore.