496 PLEURO-PNEUMONIC EPIZOOTIC AMONG CATTLE. 
tensity. After the first two or three days, their effects become 
manifest in the beast being unable to continue long down — greater 
difficulty of breathing — the expiration accompanied by a grunt — - 
absence of respiratory murmur in various parts of the lung — 
bronchial respiration round the margin of the hepatized or in- 
undated parts — increasing prostration of strength — quickened 
but feeble pulse — decrease of animal temperature — torpidity of 
the nervous system, dysentery or diarrhoea, and the accompa- 
nying fever of a low typhous character. 
By this time the pulmonary substance, incapacitated from per- 
forming its duties in the animal economy, and placed beyond the 
pale of vital action, is subjected to a chemical one. Decomposition 
takes place, and foetid effluvia are given off during the latter part 
of the beast’s existence, which now speedily terminates. 
With respect to the causes of this disease, I can say little. It 
has assumed an epizootic character, occurring in all situations 
and under all circumstances. Its first appearance in this part 
was in the neighbourhood of boggy land, and in woody localities, 
attacking more especially cattle recently brought into the country ; 
but it soon extended its ravages, and now attacks them irrespec- 
tively, in all circumstances and situations. 
With the post-mortem appearances you are already acquainted. 
Since last year I have seen cases wherein the heart was affected, 
and pericardic effusion had taken place ; but, I am inclined to 
believe, in consequence of proximity to parts already diseased, 
and not primarily. Still the characteristic feature of this disease 
is, an early effusion of lymph into the pulmonary vesicular struc- 
ture and bronchial tubes, as the termination or natural means of 
relieving inflammation existing in their parietes and parenchy- 
matous tissue generally. There is also an effusion of water and 
lymph into the thoracic cavities, as the result of inflammation 
existing on their pleura ; lymph, in most cases, forming a com- 
plete coating of great thickness to the costal and pulmonary 
surfaces, and also adhesions between the two almost through- 
out. Except the bronchial glands being occasionally in a state 
of suppuration, I have very seldom found any appearance of pus 
in this disease. 
On reading the preceding account some might suppose, and 
perhaps justly, that these symptoms and post-mortem appearances 
indicate merely ordinary bronchitis, pneumony, or pleurisy, sin- 
gly or combined, as the case may be. Should such, however, 
come to treat this affection in the way usually and successfully 
pursued in isolated cases of these diseases in horses and cattle, 
they will be, as I have been, from its almost invariable failure, 
induced to adoptanother course. 
