GASTROENTERITIS AND INFLUENZA. 
83 
that weakness of the brain and nervous system may be a cause as 
well as an effect of gastro-enteritic fever 1 To account for this 
weakness in spring and autumn, I must again direct your atten- 
tion to the coating process, and to the fact that, during that period, 
there is an increased determination of nervous energy to the skin ; 
and consequently it is in a great measure abstracted from the 
whole of the digestive organs, the result of which must be 
inability of those organs to convert the food into its elemental 
principles, or to separate the nutritious from the innutritious matter. 
Then, as the food is passed through the intestinal canal without 
affording its usual nourishment to the blood, and as the brain can- 
not remain in a healthy state without a sufficient supply of that 
fluid, can we wonder at the whole system becoming weak, and 
falling into a state of derangement or fever 1 This low fever may 
continue during the coating process, or for an indefinite period, 
without causing any thing more than mere functional derangement ; 
but if an exciting cause (such as a sudden change in the weather, 
&c.) is applied, this fever may become typhoid or malignant, or 
may terminate in inflammation of the mucous membrane lining 
either the serial passages or intestinal canal. And, if we want 
further proof than my own senses afford of this disease being 
caused by weakness, I have only to turn to Dupuy’s account of it, 
in 1825, when it assumed a vertiginous character, and was, he 
says, particularly fatal in old horses, and such as were oppressed 
with work beyond their powers, or otherwise debilitated. 
But a more familiar fact to almost every veterinary student is 
the appearance presented by an animal slowly bled to death. In 
it we perceive the quick pulse, spasmodic twitchings and pains, 
the same flatus or secretion of air in the intestinal canal, as also 
the shivering fit and sweating fit, together with vertigo, and other 
prominent symptoms of gastro-enteritis. However, what thoroughly 
convinced me of the impropriety of bleeding in this disease was 
having witnessed two cases that appeared to have nothing more 
than the ordinary symptoms about them, but they were bled, and 
both from that moment got worse ; and the fever, which, prior to 
the bleeding, was of a mild character, speedily became typhoid, 
and the consequence was death. They were both bled, I should 
add, early in the disease. In the same stable with one of those 
that died from this bleeding was another with higher inflammatory 
symptoms, and evidently worse than the one that was bled, and 
yet he recovered without losing a drop of blood. Since then, 
although I met many cases similarly affected to those three horses, 
I always abstained from blood-letting; and my success has been 
such as to convince me of the inutility of that operation in sub- 
duing this fever. 
