ORIGIN OF DISTEMPER. 60 1 



as there were 20,000 years ago ; and although we have no actual proof that a disease-germ may 

 originate in our own land, and find soil congenial to propagation in the animal called a dog, still 

 we have no proof at all that it cannot. 



Fleming, we think, does believe in the spontaneity of certain diseases. Hunting, a shrewd 

 man and close observer, does not. He defends his belief, or rather disbelief, by the following 

 arguments: (i) "That many dogs never have distemper at all." (Quite right; some people 

 manage as a rule to so order it that their dogs, seldom, if ever, contract the disease.) (2) " That 

 one attack very rarely follows another, which is the opposite to what would obtain if cold could 

 induce it/' (But cold alone will not produce it. And again, dogs who have had the disease 

 once, do not possess the same immunity from other attacks that people do who have once had 

 small-pox.) (3) " That cases of distemper often arise in dogs that have not been exposed to the 

 alleged causes." (We grant this, and these cases are doubtless the result of contagion alone.) 

 (4) " That we know the disease is contagious, and therefore in the infected dog there must be a 

 specific poison." (This we also admit.) And, lastly, that " previous to 1763 dogs were exposed to 

 all the alleged causes, and yet never showed a sign of distemper." And this last statement 

 is perhaps the strongest part of Mr. Hunting's argument. 



Concerning one thing, at all events, there remains not the shadow of a doubt in the minds 

 of any of us. Distemper is a highly contagious or communicable disease ; and as to the 

 possibility or impossibility of its arising spontaneously in our kennels, it is better to err on the 

 safe side, and protect our dogs from as many of the alleged causes as we can. 



We know for a fact that dogs may have distemper more than once in a lifetime. The 

 pathological reasons for this are expressed in beautiful language by Watson and Tyndall. 

 Referring to the exanthematous diseases of the human frame, Watson compares the growth of a 

 disorder of this nature to that of a vegetable in the field. 



" We have," he says, " the visible and tangible seed, the manifest sowing, the hidden germi- 

 nation ; then the outward growth and efflorescence, the ripening, the mature seed-time, the 

 reproduction manifold of the original specific germ every stage in the process of development 

 occupying a definite period of time. Lastly for here the analogy, though weaker, does not wholly 

 fail we have the total or the partial, the final or the temporary exhaustion of the soil, even for a 

 single crop for that particular substance. Sometimes (to continue the metaphor) the soil slowly 

 regains the power to grow the same disorder ; we see this in the waning protective influence of 

 distant bygone vaccination." 



Tyndall holds the same idea. " A tree," he said, " or a grain crop requires for its existence an 

 infinitesimal amount of mineral matter, without which, however rich the soil, it cannot grow. It is 

 perfectly conceivable that a soil may contain this matter in such minute quantity that a single 

 crop may exhaust it ; and this without prejudice to the capacity of the soil as regards other crops. 

 Now may there not, prior to the sowing of the virus, be something analogous in the human system 

 which a single crop of pustules entirely removes ? Some such change is certainly wrought, and 

 I would rather express it in terms of matter than in terms of force. If after one attack of 

 small-pox the system ever becomes receptive of a second, this would be equivalent to the restora- 

 tion of the requisite mineral matter in the soil." 



Causes of Distemper. Whether it be that the distemper virus, the poison seedling of the 

 disease, really originates in the kennel, or is the result of contact of one dog with another, or 

 whether the poison floats to the kennel on the wings of the wind, or is carried there on a shoe or 

 the point of a walking-stick, the following facts ought to be borne in mind, (i) Anything that 

 debilitates the body or weakens the nervous system paves the way for the distemper poison. 

 78 



