A: Because they can.
...I've been waiting for over 4,000 posts in 13 years of blogging to use that in a prescient way. It involves light reading, from The International Journal of Surgery, 1916:
Autotherapy is a subject the importance of which is bound to be generally appreciated when its principles are better understood. Its remarkable efficiency, simplicity of technic, and economy should appeal to the medical mind, and have already attracted wide attention. The results obtained by a host of physicians who have employed it in the treatment of localized infections, in both men and animals, surpass anything medicine or surgery has yet offered.
In its simplest form autotherapy consists of licking the wound, as animals do. This procedure has demonstrated the important fact that pus by the mouth, in wounds not connected with the alimentary tract or the respiratory system, acts therapeutically at once and the results tend to be permanent.
Physicians who have used it on themselves claim that it acts magically in boils and other purulent infections. Others, who have administered the exudate from the cervix in treating deep infections of the pelvis, assert that they are afraid to publish their results for fear their veracity might be doubted.
At the inception of autotherapy the writer employed exudates containing live pathogenic microorganisms as a therapeutic agent. Later, in an effort to make a more elegant autotherapeutic preparation, a dilution of pus was passed through a Berkefeld filter and the efficacy of the filtrate tested thoroughly both by the mouth and hypodermatically. This was found to be equally effective when given in the manner described. Here was a second medical fact or stepping-stone in the development of autotherapy. Filtering can be done by any family physician at the bed-side, and the filtrate is applicable to all localized infections. It contains the toxins from both the causative and complicating micro-organisms in the same proportions as they appear in the locus of infection. Let us remember that the antitoxins of commerce are obtained in response to the action of injected toxins. With autotherapy the patient is auto-immunized, i.e., immunized to his own toxin-complex.
The consensus of medical opinion of the many who use autotherapy in daily practice is tritely expressed by Dr. J. C. Parham, Past Assistant Surgeon of the United States Navy, who says: "I am convinced that once your method of treatment is generally known its advocates will be legion; Surely, the theory is sound, and still mare surely sound are the results."
The autotherapeutic remedy is the only strictly autogenous agent at our command in fighting disease. It is quite generally admitted that the therapeutic effect of autogenous vaccines is superior to that of stock vaccines. Yet even Wright's vaccine is lowered by every step through which it passes in the laboratory. Its therapeutic effect is altered by growing in foreign culture media, by heat, by chemical preservatives. We may not be able to grow the infecting micro-organisms outside the human body; under such conditions an autogenous vaccine cannot be prepared. It takes time to prepare Wright's vaccine and meanwhile the patient grows worse, passes the crisis, or often dies before the remedy is available. If Wright's vaccine cures, this is not due to laboratory manipulation, but in spite of it.
There is no certainty of cure with any heterogeneous toxin or set of toxins; experience for upward of a century clearly proves this. Administering stock conglomerate vaccine has been frequently termed shot-gun therapy [I've called it "carpet bombing," but we're reading from 1916, pre-WWII metaphor - Ed] pure and simple, and considered unscientific. What is new today is often old tomorrow. With the advent of autotherapy our ideas of the treatment of infections have changed, for the autotherapeutic remedy is Nature's remedy. Self-therapy or self-preservation is the fundamental principle of life. Natural therapy is the culmination of vaccine therapy. The autotherapeutic remedy will cure an acute localized infection in a thousand years from now as quickly as it does to-day, for the principle upon which it rests is everlasting and immutable.
The condemnation of autotherapy is usually in direct proportion to the ignorance or bias of the critic. The main criticism of autotherapy is that it is crude. With those who prefer so-called scientific to effective treatment of their patients, we have no basis for discussion. Natural methods may appear crude and simple. The fault is not with nature; but lies in the fact that we have moved so far away from her that we fail to appreciate or perceive the truths she holds out to us in all their bearings. This accounts for the endless speculations, controversies and uncertainties that have characterized the study of medicine through past ages. In spite of all of our vaunted knowledge, it is, perhaps, humiliating to be told that the patient brings his natural remedy with him in his body to the physician, and that it often can be obtained.
That was in 1916, and Duncan's warnings are only more prescient 99 years later, still unheeded in the name of carpet-bombing antibiotics that can make huge profits for drug companies.
When I was forwarded that by one of the many collaborators who copy me—because they never know that when something becomes of serious interest to me on many levels of health—including drug company profits and their bedfellow functionaries in positions of power—it goes on out here to thousands in form of payment for their efforts.
...You'd never know, unless I told you, that it began days ago as a thread between about 5 people exploring the idea of urine-drinking therapy, which the consensus is still very undecided and skeptical about, as indistinguishable from placebo, basically.
As well, how is pee drinking (comes down to like "homeopathic" in the stuff I've been asked to read—like just a drop on the tongue) differentiated from modern proclivities involving sucking cock and eating pussy? To me, it's a human-animal proclivity to enthusiastically exchange bodily fluids. ...A 10-second open mouth kiss transfers about 80-million microorganisms.
And mamalian mom's transfer kagillions of stuff to their infants, for another dot. But yet another dot: infants may transfer back pathogens for mom's breasts to create antibodies. Whoa, eh?
Breastmilk protects infants against infections; however, specific responses of breastmilk immune factors to different infections of either the mother or the infant are not well understood. Here, we examined the baseline range of breastmilk leukocytes and immunomodulatory biomolecules in healthy mother/infant dyads and how they are influenced by infections of the dyad.
In addition to maternal infection, a small but significant breastmilk leukocyte response was observed when the infant had an infection, but the mother was asymptomatic. This finding is supported by a recent study from Riskin et al. that also reported a response of breastmilk leukocytes to active infection of nursing infants.
While the mechanism behind the leukocyte movement into the breast during an infection of the infant is still unclear, exposure of the mother to the infant's infection may stimulate an immunological response in the mother that is manifested without evident symptomatology, but which influences breastmilk leukocyte content.
A potential way for this to happen is during breastfeeding. During a milk ejection, duct pressure increases, milk ducts dilate and milk flows toward the nipple / baby's mouth. As oxytocin wears off, duct pressure decreases, milk ducts reduce in size and milk flows backwards, likely together with saliva from the baby's mouth. This is a time when it is possible that microorganisms from the infant could be transferred back into the breast, most likely during a pause in suckling, stimulating a local immune response.
Or, go to any of thousands of "Paleo" sites now, and order up your "Paleo" brownies, and take sweet pleasure that you know it all while reading the same things you've been reading for years. Go read Cordain, whose known it all since 2,000 and spends all of his time asserting that he's known it all, since 2,000.
Did you catch it though? Mammals created biological WiFi eons ago in the form of both beneficial and potentially pathogenic microorganism transfer via tits.
No wonder society worships them (I like small-rockets, just so you know).
Oh, any microbiologic horizontal gene transfer going on? I don't know. But I know who to ask.
Let me tell you why I jumped off my ass and created this post:
I have always licked my wounds I can reach, for one; and, to admit to it, if I missed something like a bit of wood from a splinter and it festered, I'd always pop it, lick up the tasty puss, and keep licking the wound. Since I was a kid. All my wounds healed remarkably fast and the way I spent my childhood on my grandfather's 10 acres next to the Truckee River outside Reno, NV, I was always sporting wounds as a function of natural environment.
In follow-on collaboration, I was admonished to emphasize that it's not just licking fresh wounds that's important, but perhaps more important, festering ones, where you take up the pussy antibodies.
It's the very first time I ever told anyone: because, y'know, I got "socialized," too.
Free the Animal.