FUNDAMENTAL PRINCIPLES OF DISEASE. 41 
acute one; without alteration of blood the mucous membranes become 
of a rosy or deep-red color at the outset; if the fever is attended with 
distinct alteration of the blood, as in influenza, and at the end of two 
cr three days in severe cases of pneumonia or other extensive inflam- 
matory troubles the mucous membranes are tinged with yellow, which 
may even become a deep ocher in color, the result of the decomposi- 
tion of the blood corpuscles and the freeing of their coloring matter, 
which acts as a stain. At the outset of a fever the various glands 
are checked in their secretions, the salivary glands fail to secrete the 
saliva, and we find the surface of the tongue and inside of the cheeks 
dry and covered with a brownish, bad-smelling deposit. The excre- 
tion from the liver and intestinal glands is diminished and produces 
an inactivity of the digestive organs which causes a constipation. 
If this is not remedied at an early period, the undigested material 
acts as an irritant, and later we may have it followed by an inflamma- 
tory process, producing a severe diarrhea. 
The excretion from the kidneys is sometimes at first entirely sup- 
pressed. It is always considerably diminished, and what urine is 
passed is dark in color, undergoes ammoniacal change rapidly, and 
deposits quantities of salts. At a later period the diminished excre- 
tion may be replaced by an excessive excretion, which aids in carrying 
off waste products and usually indicates an amelioration of the fever. 
While the ears, cannons, and hoofs of a horse suffering from fever 
are usually found hot, they may frequently alternate from hot to cold, 
or be much cooler than they normally are. This latter condition: 
usually indicates great weakness on the part of the circulatory system. 
It is of the greatest importance, as an aid in diagnosing the gravity 
of an attack of fever and as an indication in the selection of its mode 
of treatment, to recognize the exact cause of a febrile condition in the 
horse. In certain cases, in very nervous animals, in which fever is 
the result of nerve influence, a simple anodyne, or even only quiet 
with continued care and nursing, will sometimes be sufficient to dimin- 
ish it. When fever is the result of local injury, the cure of the cause 
produces a cessation in the constitutional symptoms. When it is 
the result of a pneumonia or other severe parenchymatous inflam- 
mation, it usually lasts for a definite time, and subsides with the 
first improvement of the local trouble, but in these cases we constantly 
have exacerbations of fever due to secondary inflammatory processes, 
such as the formation of small abscesses, the development of second- 
ary bronchitis, or the death of a limited quantity of tissue (gangrene). 
In specific cases, such as influenza, strangles, and septicemia, there 
is a definite poison in the blood-vessel system and carried to the 
heart and to the nervous system, which produces a peculiar irritation, 
usually lasting for a specific period, during which the temperature 
can be but slightly diminished by any remedy. 
