The cough so varied in health and in disease deserves careful practical
study. It can usually be excited in solipedes, sheep and dogs by
pinching the first ring of the windpipe between the thumb and first two
fingers. In oxen it is best produced by compressing the anterior part of
the larynx. In old cattle it is difficult to produce coughing. In no
animal should the attempt be made rudely nor unnecessarily repeated, as
it may tend to excite or to aggravate already existing sore throat.
The cough of the healthy _horse_ is _sharp_, _loud_ and _ringing_, often
repeated two or three times and followed by a snort (clearing of
himself). It is weaker in young horses and shorter and drier in the
aged.
The usual cough of the _ox_ is _weak_, _dry_, _slightly husky_ and
_prolonged_.
That of the _sheep_, _small_, _weak_ and _dry_.
That of the _dog_, also weak and dry.
A =strong, full, deep, ringing cough= is rarely heard in disease except
in slight irritation of the larynx. In such cases the larynx is tender
and slight handling or pinching develops the cough.
A =weak cough= wanting in resonance and heard only at a short distance
from the horse, is usually associated with chronic chest diseases and
the last stages of acute thoracic inflammations.
A =short=, =broken= or =abortive cough= is one which appears to be
suddenly cut short and suppressed, from the pain it causes. It is seen
in the early stages of inflammations of the serous membranes of the
chest or abdomen, when the quick rubbing of the dry and inflamed
surfaces of these membranes on each other produces exquisite pain. It
characterizes especially the _debut_ of pleurisy, pleuro-pneumonia and
peritonitis. This cough is infrequent for the same reason that it is
short.
A =dry=, =loud=, =rasping=, or =croupous cough= is peculiar to the early
stages of laryngitis, tracheitis and bronchitis, when the membrane is
swollen, tense and dry. It is equally met with in diphtheritic and
croupous affections implicating the larynx.
A =small=, =weak=, =dry=, =husky cough= without any _rasping_ is
characteristic of broken wind (heaves) emphysema of the lungs, asthma,
or chronic bronchitis.
A =soft=, =humid= or =rattling cough= exists in the advanced stages of
laryngitis, bronchitis and pneumonia when the activity of the
inflammation has given way and a free exudation has taken place from the
mucous membrane. It is usually accompanied by a discharge, in solipedes
from the nose, and in other animals from nose and mouth.
A =soft cough= with a peculiar gurgling in the larynx is sometimes met
with in croup.
A =paroxysmal cough= is one repeated five, ten, or twenty times in rapid
succession. It is common in chronic bronchitis, early heaves, emphysema,
verminous bronchitis and influenza. In such cases it is observed chiefly
when the subject is brought out to the cold air, when he takes a drink
of cold water, or when he has just had some active exertion, or some
dusty or fibrous food.
A =symptomatic cough= is one due to disease in some other organs than
the respiratory, and which irritates the air passages through nervous
sympathy (reflex action). It is commonly small, short and dry.
Inflammation or other disease of the liver, indigestions and intestinal
worms are occasional causes of symptomatic cough. In the case of worms
it may be loud, clear and ringing.