494 
ON PUERPERAL FEVER IN THE COW. 
are all perfectly aware of the physiological truth that any organ, 
ceasing to perform its usual action in the animal frame, cannot 
suddenly resume them : in fact, we know that, if it be suspended 
for any undue time, it is incapable of being again re-exercised. 
Although this may apply less to the udder than any other organ, 
still it must be confessed at times to fall within the general appli- 
cation of this principle, and not after all cases of parturition to re- 
gain its former activity. 
Parturition, by separating the foetus and its membranes from 
the maternal uterus, involves a sudden and complete check to the 
current of blood, recently required by it in utero, being now pro- 
vided with means of sustaining an independent life, dependent, 
nevertheless, still on its parent for food — namely, milk, and that 
milk secreted from the circulating fluid, previously imparting nutri- 
tion in another form and through another channel. Should, then, 
any constitutional or other cause interfere, so as to prevent a se- 
cretion of milk, in full proportion to the existence of its elements 
in the system, or this effect be produced by any tardiness of the 
udder in resuming its functions, we can easily conceive that, under 
such circumstances, some organ, or class of organs, previously 
wrought upon by unusual stimuli, would, from the consequent pre- 
disposition thereto, assume a diseased function. Thus, I infer, arises 
one great, if not the greatest, cause of inducing puerperal fever. 
That the nervous centres are at this time more than any other 
susceptible of morbid impressions, we have a right to infer ; indeed, 
this is so far admitted, that many practitioners are of opinion that 
the cow is, during her later period of gestation, in a constant state 
of excitement or slight sympathetic fever. 
It will, then, be evident that cows yielding large quantities of 
milk, and kept on stimulating food before calving, must be ex- 
tremely liable to this disease. Of this we have daily evidence in 
its frequent occurrence among farmers and dairy keepers, whose in- 
terest or pride it is to create as much milk as stimulating food will 
produce ; and of its comparatively rare occurrence among others 
who habitually, either from neglect or poverty, keep their cows 
lean. It is, indeed, proverbial, in some districts, that fat cows, if 
good milkers, are pretty certain to be attacked by " milk fever,” a 
name, among professional men, now in disuse, but one, like many 
others, arising from observation, and certainly more proper than that 
which is now generally adopted. In no one instance do I remember 
to have seen it occur in a bad milker, however fat, for in these 
comparatively non-vascular constitutions there is not a sufficient 
quantity of blood to throw back upon the constitution and operate 
injuriously. It is also worthy of remark, as tending still further 
to confirm this view, that cows of this description have uni- 
