70 CLINICAL BACTERIOLOGY AND 



through a conglomeration of circumstances, fails to rise to 

 the occasion, the immunizer should step in, and with his 

 vaccines supply the essential stimulus which is needed to 

 produce the various antibodies which she requires to battle 

 against bacterial invasions. 



Some animals are born with a lesser degree of resistance 

 to a bacterial infection than others; and also this dimin- 

 ished resistance is particularly noticeable in certain strains 

 of families, and this fact often led the older practitioners 

 .astray, when, by reason of the persistent recurrence of the 

 disease in several succeeding generations, they insisted that 

 the condition must be hereditary, when there was nothing 

 more inherited than a weakened resistance. It is in cases 

 such as these that vaccine-therapy can do so much. With 

 this as with all other systems of treatment, an orthodox 

 line laid down and dogmatically followed is almost certain 

 to lead to failure and mistrust, and it is probable that there 

 is no other system of medicine which requires more fore- 

 thought, more precision, and more careful analytical study, 

 on the part of the immunizer, than vaccine-therapy. For 

 example, an animal may develop strangles, the disease 

 becomes pysemic, and in due course we clear the system with 

 a streptococcal vaccine. All that now probably remains is a 

 rectal fistula, which we fail to close, and after some further 

 extended trial we give vaccine -therapy up as hopeless. 

 We may even scarify the sinus, plug and dress, and yet fail 

 to get good results. We make a microscopical examination 

 of the pus, and find we are dealing with a mixed infection 

 — for example, a secondary infection by staphylococci — 

 and in addition, being near the anus and rectum, perhaps 

 B. coli have become established. The system of treatment 

 has been condemned in failing to complete a cure, but how 

 could a streptococcal vaccine cure a staphylococcal and coli 

 infection ? In short, the onus of failure rests with the 

 immunizer in this case. Again, take a case of poll-evil, 

 where, the infection being unusually severe, necrosis 

 of a piece of deep-seated tissue follows, which would in 



