SERUM PREVENTIVE TREATMENT OF CATARRHAL 
FEVER IN HORSES.* 
By John T. Shannon, V.S., Lexington, Ky. 
Catarrhal fever, influenza, stockyard fever or shipping fever 
is a highly contagious and infectious febrile disease, character¬ 
ized by an elevation in temperature and a catarrhal condition of 
some mucous membrane of the body. 
It is a disease of the horse, mule and ass. All horses are sus¬ 
ceptible, especially the younger animal. Catarrhal fever is a 
term used to include a variety of symptoms. This disease is not 
unlike la grippe in man. It is not a new disease, but, on the 
other hand, very old—1299 A. D. 
At first there is an elevation of temperature and increased 
pulse, but as the disease advances it becomes localized. The 
cause has not exactly been determined, but, like all infectious 
diseases, there has been a large number of baoteriologic exam¬ 
inations conducted for the purpose of determining the cause. In 
1892 one bacteriologist found a bacterium. The observer men¬ 
tioned found the same organism in the blood and the purulent 
bronchial discharges. The specific organisms are bacilli very 
small in size, having the same diameter as the bacillus of mouse- 
septicsemia, but only about half as long. They are usually soli¬ 
tary, but may be united in chains of three or four elements. 
They stain rather poorly; sometimes these bacilli stain more 
deeply at the ends than at the middle, so that they appear not a 
little like diplococci. The bacillus is non-motile and, so far as 
is known, does not form spores. It cannot be positively proven 
that this bacillus is the cause of influenza, but from the fact that 
it can be found only in cases of influenza, as long as the puru¬ 
lent secretions last and then disappears, the discoverer was able 
* Presented at Kentucky Veterinary Medical Association, February, 19x2. 
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