INFLUENZA— EPIZOOTIC. 865 



try, and attacking a number of horses at the same time. In its 

 nature it resembles an epidemic form of catarrh, but it is essentially 

 different, and is easily distinguished from that complaint by its 

 epizootic character, and the marked prostration, and low typhoid 

 form of fever which ah^^ays accompanies it. It does not affect 

 Shorses alike in all seasons ; some years it is apt to involve the 

 lungs principally, with a marked tendency to di'opsical effusion, 

 whereas in others the liver and digestive organs are chiefly im- 

 plicated. 



Causes. — It is usually supposed to arise from " atmospheric 

 causes, ' — some changes which ai-e said to exist in the atmosphere 

 which are not easily explained. It occurs mostly in spring or 

 autumn, and is most commonly seen in over-crowded, badly-ven- 

 tilated stables, situated in malarial districts. City horses are more 

 liable to it than those in the country, and coarser breeds are more 

 subject to it than the finer bi'eeds. Poor and over- worked horses 

 are especially subject to the fever. 



The disease at times comes on as an epizootic. While it is 

 considered decidedly contagious, many veterinarians claim no in- 

 fection. Dr. Mever informed the writer that while the fever was 

 at its height, in one stable where the sanitary conditions were ex- 

 cellent, and containing one hundred and seventy horses, not an 

 animal was taken with the fever ; while in badly ventilated stables, 

 and under poor conditions, the disease was rampant. 



This is not, however, fully in harmony with the writer's 

 experience. In 1871, when the fever was very prevalent in the 

 East, to avoid the disease he shipped his horses from Central New 

 York to Mansfield, Ohio. Tlie horses were all in perfect health, 

 and the conditions of care and stabling were the very best possible ; 

 yet when the epizootic reached the town, the first day there were 

 reported in different parts of the place fully fifty horses that were 

 taken with the disease. The writer's horses, five in number, were 

 all taken the same day ; one or two of them but slightly, two of 

 them veiy severel}^ 



Country people, with the hope of avoiding the disease, would 

 hitch their horses about a mile outside the city limits ; but it was 

 soon found this made no difference, as horses running in the fields 

 seemed to be equally subject to it, though not, as a rule, very 

 severely. One farmer who left his horse as stated, far beyond the 



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