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Diseases  of  Cattle  and  Sheep. 
rally  speaking,  most  of  them  are  dirty,  undrained,  exposed  places,* 
where  the  youngest  and  weakest  are  deprived  of  their  proportions 
of  roots  and  shelter,  the  older  ones  taking  the  greater  share. 
I have  frequently  observed  that  cattle  can  bear  cold  with  indif- 
ference during  dry  weather,  but  they  look  out  for  shelter  on  the 
approach  of  rain.  As  far  as  our  feelings  are  concerned,  the  sen- 
sation experienced  in  dry  cold  air  is  rather  an  increase  of  activity 
than  otherwise  ; whilst  humid  air,  at  an  equal  temperature,  pro- 
duces a sensation  of  cold,  that  seems  to  penetrate  the  whole 
system,  and  particularly  disposes  the  skin  to  paleness  and 
shivering.  If  we  may  reason  from  analogy,  cold  and  rain  act  in 
a similar  manner  on  cattle,  producing  internal  disease  by  de- 
ranging the  circulation,  particularly  the  capillaries,  and  causing 
congestions  of  internal  organs. 
Catarrh  is  oftentimes  induced  in  this  manner.  This,  in  the 
strict  sense  of  the  term,  commonly  called  cold , consists  of  inflam- 
mation of  that  portion  of  the  mucous  membrane  of  the  air- 
passages  which  lines  the  nostrils,  but,  if  neglected,  is  sometimes 
apt  to  extend  beyond  the  nostrils,  when  it  may  produce  bronchitis, 
which  is  a highly  dangerous  disease  and  requires  prompt  atten- 
tion and  all  the  aid  that  veterinary  skill  can  afford.  Cough  creeps 
on  insidiously  in  both  cattle  and  sheep.  When  the  disease 
reaches  the  bronchi  the  cough  has  a frequent  painful  husking 
sound,  and  is  easily  recognised  by  the  anxious  haggard  look  and 
rapid  laborious  breathing  of  the  poor  beast. 
Catarrh  is  sometimes  epizootic,  that  is,  there  is  something  in  the 
air  which  oftentimes  produces  house  of  a dangerous  character, 
beyond  what  is  perceived  by  our  senses.  This  is  clearly  shown 
by  the  very  general  or  epizootic  prevalence  of  the  affection  at 
certain  seasons  or  certain  character  of  winds  or  weather.  Fever 
is  almost  invariably  present  in  those  cases,  not  always  of  the  same 
character — sometimes  active,  at  other  times  of  a low  typhoid 
kind : and  of  late  years  this  constitution  or  type  has  more  or  less 
prevailed  amongst  horses. 
Temperature  in  extremes,  or  sudden  transitions  from  heat  to 
cold , is  a frequent  cause  of  disease  in  youny  cattle. 
* The  nature  of  the  subsoil  is  of  the  greatest  importance  in  determining  the  spot  for 
erecting  farm  buildings,  as  dryness  of  the  surrounding  air  is  most  permanently  obtained 
in  connexion  with  a soil  from  which  the  water  of  rain  and  dew  speedily  drains  oil',  or 
evaporates,  as  on  rocky  surfaces;  or  sinks  deeply,  as  in  sand,  chalk,  and  light  gravel. 
Cold  damp  air  constantly  surrounding  undrained  straw-yards  is  proverbially  unhealthy, 
and  its  disordering  action  may  be  in  great  measure  traced  to  its  physical  properties  of 
abstracting  heat  and  electricity,  and  of  checking  perspiration  and  assimilation,  which 
it  obviously  does.  Dry  air,  on  the  contrary,  at  moderate  temperatures,  facilitates  the 
purification  cf  the  blood  in  the  lungs  by  improving  the  tone  of  the  moving  fibre,  by 
checking  tendencies  to  excessive  secretion,  and  by  counteracting  various  septic  pro- 
cesses within  and  without  the  body,  and  it  is  one  of  the  best  safeguards  against  the 
activity  of  miasmatic  poison,  which  is  generally  promoted  by  humidity. 
