Canine  Distemper. 
247 
it  was  for  this  reason  that  the  Committee  referred  to  above 
determined  to  test  the  efficacy  of  the  vaccin,  bj"  experiments 
carried  out  under  conditions  that  would  be  more  likely  to 
show  whether  it  had  any  real  value. 
The  plan  of  the  experiments  was  to  take  an  equal  number 
of  young  dogs  belonging  to  the  same  litters,  and  which  had 
never  had  distemper,  and,  wdiile  vaccinating  one  set  according  to 
the  method  of  M.  Phisalix,  to  leave  the  other  set  unvaccinated, 
the  latter  serving  as  control  animals  when  both  sets  were 
afterwards  exposed  to  the  contagion  of  distemper. 
In  the  experiments  carried  out  at  the  Royal  Veterinary 
College  the  animals  used  were  drawn  from  two  litters  of 
puppies,  viz.,  four  collies  and  four  Irish  ten-iers.  Two  of 
each  were  vaccinated  with  Phisalix  vaccin,  and  after  several 
weeks,  during  which  the  whole  eight  puppies  appeared  to  be 
quite  well,  they  were  simultaneously  exposed  to  infection  by 
placing  among  them  dogs  suffering  from  distemper.  Both  in 
the  case  of  the  collies  and  the  Irish  terriers  the  results  were 
entirely  opposed  to  the  view  that  the  vaccination  had  conferred 
any  protection  against  distemper.  The  first  animals  to  contract 
the  disease  after  exposure  to  infection  were  the  two  vaccinated 
collies,  and  both  of  them  died  in  consequence.  The  two  un- 
vaccinated collies  also  became  affected,  but  while  one  of  them 
died  from  distemper  the  other  recovered. 
In  the  case  of  the  Irish  terriers,  one  vaccinated  and  one 
unvaccinated  pup  caught  the  disease  and  died  from  it,  while 
the  other  two  (one  vaccinated  and  one  unvaccinated)  survived, 
and,  indeed,  never  developed  any  distinct  evidence  of  the 
disease. 
In  face  of  these  results  it  is  impossible  to  maintain  that  the 
operation  had  been  of  any  value  to  the  four  vaccinated  animals. 
There  are  also  grounds  for  believing  that  the  bacterium  present 
in  the  vaccin  has  nothing  whatever  to  do  with  distemper,  and 
that  this  is  the  reason  why  the  vaccin  fails  to  confer  any 
protection. 
J.  McFadyean. 
Ro}-al  Veterinary  College,  Camden  Town. 
