When the therianthropic online community was in its infancy, many terms were adopted out of convenience, and as ideas were being fleshed out. In the beginning, the first discussions were by the members of AHWW. They felt as if they were in some fashion, something like a werewolf, but not physically. Therefore, the term "spiritual werewolf" was used in an attempt to discuss these feelings. It became, to a degree, a placeholder for concepts that hadn't been discussed.
Eventually, this term fell out of use as more specific terms- such as therianthropy- were constructed.
Please see the page for Spiritual Therianthropy to learn more.