INFLUENZA. 
21 
INFLUENZA. 
By T. D. Hinebatjoh, M.S., V.S. 
SYNONYMS: —Epidemic Catarrh; Epizootic Catarrhal Fever; 
Panzootic Catarrhal Fever ; Distemper ; Epizootic. 
Influenza in its various forms has been recognized for cen¬ 
turies, and prevails to a greater or less extent, at all times and 
at all periods of the year, and in all countries where horses 
are used. Its character varies somewhat with the season, it 
being more severe at some seasons of the year than at others. 
Definition. —Influenza is essentially a contagious and in¬ 
fectious febrile disease, involving few or many organs of the 
body, such as the lungs, pleura, heart, liver, spleen, kidneys 
and intestines. It also attacks the joints, in some instances 
proving very serious. Its virulence will vary according to 
the organ attacked, also with the extent of the disease. Ill 
ventilated stables, or stables where the surroundings are bad, 
greatly increase the severity of the disease, and are often the 
immediate cause of the death of animals from this affection. 
Causes. —Influenza is due to the introduction of a specific 
micro-organism, the true nature of which is as yet little un¬ 
derstood. Influenza prevails on every kind of soil and geo¬ 
logical formation, at all seasons and temperatures ; however, 
it more often exists during autumn, winter and spring, than 
during the summer months ; atmospheric conditions have no 
direct influence in producing the disease, but may increase its 
virulence. 
Predisposing Causes.— Although the disease is a conta¬ 
gious and infectious one, yet there are conditions which ren¬ 
der the animal more susceptible to the action of the virus, 
among which are damp, ill ventilated or overcrowded stables; 
age plays an important part, young horses suffering more fre¬ 
quently than aged ; bad food; over work ; neglect of every 
description; change of climate and change of location, as 
from the country to the city and vice versa; changing from the 
pasture to the stable, especially if poorly ventilated, or from 
the stable to pasture. The greatest cause, however, is com- 
