Therianthropy vs. clinical lycanthropy
Spiritual therianthropy is not automatically the same as clinical lycanthropy, a mental illness in which an individual believes he or she belongs to or can change to another species. While some therianthropes believe they can take on the mindset of their "other side" in what is referred to as a mental shift, they usually believe that they retain control during these transformations and are no greater danger to themselves or others.
Likewise, people who call themselves shapechangers as a form of social identification are generally not considered ill by mental health professionals unless their beliefs interfere with the normal functioning of their lives. This can be a controversial issue, as the line between what the Western mind passes off as a strange or alternative belief and what is considered a mental illness is indistinct.
Therianthropy vs. multiple or split personality
Most therians do not assert that they have multiple or split personality (also known as dissociative identity disorder) in the clinical sense. That said, since therianthropy involves at least the inner experience of dual (ie human and non-human) natures of some kind, it is reasonable to expect that the two may seem on the surface to share in common at least some dissociative traits.
At least one key difference seems to be that most therians see this as being part of their nature, rather than a dysfunction or psychological defence mechanism, thus it is often valued rather than hoped to be "cured". Another is that for dissociative identity disorder, the other personalities represent usually other or the same human personalities, and specifically fragments of repressed, alternative or childlike personality representative of the defence, that is (in laymens terms), they may represent the anger a person has, or the cunning, they may represent the splitting of personality to protect the mind in the aftermath of a traumatic sexual abuse, an alcoholic vs a sober personality, and so on.
Phenomenologically, this is very different from the consistently identified range of features of the therian personality and experience.
Therianthropy vs. body dysmorphic disorder (BDD)
In some cases, one could probably classify therianthropy as a form of dysmorphia (a non-clinical term meaning a strongly held belief that one is not in the body that one should be in, or a general dissatisfaction with the form or capabilities of one's appearance). In that sense, therians who feel this way are similar to those who seek gender reassignment, or who undergo body modification in other ways.
While some therians feel that their human body could be improved by being more animal-like, their desires in this direction have little to do with the desire to be normal or beautiful that usually characterizes BDD and eating disorders, or the dissatisfaction with a particular appendage that plagues the apotemnophiliac. It is more similar to transsexualism and gender identity disorder, where there is a persistent feeling that one "should have been" the other gender and a feeling of discomfort or inappropriateness about playing one's biological gender role, rather than looking for acceptance from others.
as in those who regard themselves as essentially non-human animals in human bodies. The terms species dysphoria and transspeciesism have occasionally been used to refer to the latter phenomenon, in parallel with the concepts of gender dysphoria and transsexuality.
Although only superficial body change (rather than major biological transformation) is surgically possible at this time, the request for surgical modification of the teeth (canine implants or by vampire lifestylers) is common enough that it is now a well-documented form of cosmetic dental surgery that is readily available in many places to those seeking it. Similarly, the recent trend towards more extreme and/or more realistic tattooing in the neo-tribal and modern primitive veins has seen a sharp rise in humans sporting large patches of naturalistic or stylized animal pattern tattooing (zebra, leopard, etc.) - nearly whole-body in the cases of the most extreme practitioners. Other forms of body modification such as horns, ear shaping (cat, elf, or vulcan style), and the like are already available, albeit uncommonly as of this writing. It is likely that over time, other elective surgical procedures of this kind will become available.
Therianthropy vs. furry fandom
Therianthropy should not be confused with furry fandom or the furry lifestyle, though some intermixing of the groups does occur. As a general rule, to an extent, therianthropes are more focused on the sense of an animal within, an animal side to their nature, or spiritual concepts; by contrast, furries are more commonly focused on furry art and/or role-playing related to anthropomorphic non-humans. There is some overlap with those who identify themselves with each group or view the other positively, as well as those in each group who view the other negatively.
Stereotypically, it is said that furries view therianthropy as "taking it too far" or "too seriously", while therianthropes assert that furries are frivolous, juvenile, and/or don't respect or understand the true nature of animals.