To me, sexual expression is a VERY deep part of my therianthopy, and for years, I have remained silent about it because of the flak I received from other therians about my sexual expressiveness. Even though I was part of the original discussion that made therianthropy a religion for all intents and purposes.
I remember when the term Therianthropy was coined... When we were having the spiritual lycanthropy thread on alt.horror.werewolves, and all the folks who identified with other animals wanted a more inclusive term. A lot of that stemmed from the thread about "Dancing your animal" ... Dancing your animal is a native american term for costuming to symbolize a spiritual celebration, and communication with your animal spirit, and that opened the door to something of a spiritual lycanthropy discussion.
In the kinky world I have discovered my own "mental shift" that most kinky people call a "head space" . I I like to apply Dr Paul Mclean's "Triune brain model" to describe the mental shift or head space as a behavior model to describe the peeling away fo the "human consciousness" of the neo cortex, and a regression into the "R-complex" instinctual anamistic behavior of he brain. While the triune brain model is totally inappropriate for a physical model, it does provide a very convenient behavioral model by which to describe the transition of consciousness, and control from human consciousness to the raw pure animal mind, driven and controlled by instinct.
This transition or mental shift is , to me a very cathartic process that I find to be emotionally, and spiritually therapeutic. I happen to achieve it through dancing my animal with fetish attire, and kinky sex acts, but this is not the case for all therianthropes.