REVIEW— ON THE EPIZOOTIC IN CATTLE. 627 
stomach. It is found to a greater or less extent in all inflammatory 
affections of cattle. 
“ The bowels are sometimes much inflamed, especially if large 
quantities of purgative medicine have been given. This, however, 
is not a metastasis, but an extension of the inflammation.” 
Although nobody pretends to deny the general resemblance 
between pleuro-pneumonia in cattle and the disease which goes 
by the same, or some similar name, in horses, yet are there certain 
points of difference in the two maladies which would induce us to 
believe their natures or essences to be distinct. One of the most 
striking of these is the contagious property of the one and the non- 
contagious nature of the other. In cattle pleuro-pneumonia Mr. 
Dun unhesitatingly declares for contagion. “As much difference 
of opinion exists on this subject (causation), it cannot be denied,” 
he says, “ that CONTAGION is a most active cause in the diffusion 
of the disease.” And in another place he adds, — “ Not only were 
the earlier cases which occurred in this island distinctly proved to 
have arisen from contact with the Irish droves, but also subsequent 
cases, even up to the present day, shew numerous examples in 
which contagion is clearly and unequivocally traceable .” Mr. 
Waters, although he does not speak in the same confident terms as 
Mr. Dun, still very satisfactorily admits the fact of the disease 
being contagious. “ A reference to our cases in general, but to 
Cases 14, 15, 18, 22, and 29, in particular, will, we think, satis- 
factorily shew that it is chiefly due to the introduction of drifted 
cattle to home stock ; and the fact of the latter, which were pre- 
viously in good health, becoming affected after being brought into 
communication with the drifted or diseased cattle, establishes in 
our mind the proof , THAT THE DISEASE IS INFECTIOUS.” Now, 
that we have a disease common among horses resembling in its 
symptoms and post-mortem relics pleuro-pneumonia in cattle, is, 
on all sides, acknowledged ; but that such disease is contagious in 
horses — although it may be of an epidemic character — is more 
than we are at present prepared to assert. 
Another great apparent difference between the diseases in the 
ox and horse is, that pleuro-pneumonia in cattle has hitherto proved 
an extremely fatal disease ; a disease a great deal more fatal, 
generally speaking, than any influenza or epidemic of the kind 
