Tuberculosis. 
39 
The  first  step  in  all  cases  must  be  to  endeavour  to  ascer- 
tain what  progress  the  disease  has  already  made  in  the  herd 
by  having  every  animal  in  it  tested  with  tuberculin.  It  has 
already  been  said  that  this  test  when  properly  carried  out  is 
very  reliable,  and  a condition  precedent  to  any  attempt  to 
eradicate  the  disease  is  implicit  acceptance  of  the  view  that 
when  an  animal  reacts  to  tuberculin  it  is  tuberculous.  It  is 
possible  that  there  are  still  owners  in  this  country  who  regard 
the  test  as  valueless,  or  at  least  very  uncertain  in  its  results. 
It  is  not  proposed  to  argue  the  question  in  this  article,  but 
merely  to  say  that  the  owner  who  refuses  to  accept  the  test 
as  trustworthy  shuts  the  door  against  all  efforts  to  give  his 
herd  a clean  bill  of  health. 
In  saying  that  the  test  is  very  reliable,  it  was  the  original 
method  of  employing  it — the  subcutaneous  test — that  was 
referred  to,  but  account  has  to  be  taken  of  the  fact  that  some 
of  the  newer  methods,  and  especially  the  “ eye  test,”  when 
used  in  combination  with  the  subcutaneous  test,  mark  a very 
important  advance  in  the  diagnosis  of  tuberculosis.  It  is 
probably  no  exaggeration  to  say  that  one  can  now  use  the  test 
in  such  a way  as  to  make  it  almost  impossible  for  a case 
of  tuberculosis  to  escape  detection.  Should,  however,  the 
result  of  the  test  appear  to  be  ambiguous  in  the  case  of  a few 
animals,  it  is  essential  for  elimination  purposes  that  these 
should  not  be  regarded  as  healthy.  Assuming  that  the  herd 
has  not  been  tested  before,  the  safest  plan  is  to  class  all  the 
animals  giving  doubtful  reactions  as  tuberculous. 
As  soon  as  the  test  has  been  carried  out  the  diseased  and 
the  healthy  must  be  permanently  separated.  If  this  is  not 
possible  any  hope  of  eradicating  the  disease  must  be  abandoned. 
Assuming  separation  to  be  practicable,  the  buildings  intended 
for  the  reception  of  the  healthy  animals  must  be  thoroughly 
cleansed  and  disinfected.  Cleansing  must  precede  the  use  of 
disinfectants,  and  is  scarcely  less  important.  The  choice  of 
disinfectant  is  not  of  prime  importance.  Carbolic  acid  and 
chloride  of  lime  are  both  reliable,  and  the  great  point  is  to 
use  them  unsparingly.  The  whole  interior  of  the  building 
should  receive  attention,  but  the  parts  most  likely  to  be 
dangerous  are  the  floor,  feeding  troughs,  and  walls  and 
partitions  to  a height  of  six  feet  from  the  ground.  Twenty- 
four  hours  after  disinfection  the  cattle  may  be  introduced. 
The  point  which  has  next  to  be  mentioned  is  one  whose 
importance  cannot  be  exaggerated.  It  is  that  the  result  of  the 
first  test  must  not  be  accepted  as  final  and  conclusive  in  the 
case  of  the  animals  that  have  not  reacted.  Neglect  of  this  in 
the  past  has  probably  been  more  responsible  than  anything 
else  for  disappointment  and  partial  failure  in  attempts  to 
