INFLUENZA OF THE HORSE 349 



fully recovered foiirteen days after the temperature has 

 become normal. 



Infectious Fibrinous Pneumonia of the Horse (Chest 

 Plague; Pectoral InUiienza; Pleurisy; Shipping Fever.) — Defi- 

 nition. — 'An acute, febrile, contagio-infectious disease of the 

 horse which in typical cases appears as a fibrinous pneu- 

 monia or pleuropneumonia with which is associated inflam- 

 mation of the subcutis and tendon sheaths. In mild cases 

 it may assume the form of a general, febrile disease of short 

 duration. 



Occurrence. — ^Infectious fibrinous pneumonia is wide- 

 spread, occurring in all countries. Statistically it is difficult 

 to state, however, anything definite in regard to its preva- 

 lency as it has been so often confused with influenza. The 

 disease is most apt to appear in large stables in which many 

 horses are kept, and especially during inclement weather. 

 The disease in passing through a stable does not usually affect 

 the horses in the order in which they stand in the stalls, the 

 infection tending to spread unevenly, skipping apparently 

 susceptible horses. Infectious pneumonia does not become 

 epizootic as readily as does influenza; it is more apt to 

 remain confined to an infected stable, from which it may be 

 spread, however, by a convalescent horse. While infectious 

 pneumonia will not involve in a given country as many horses 

 as influenza, on account of its higher mortality and a greater 

 tendency to leave behind sequels ("heaves," relapsed cases) 

 which may permanently impair the efficiency of the horses 

 attacked, it can assume even greater economic importance. 



Etiology. — ^The cause of infectious pneumonia of the horse 

 has not yet been identified. According to Gaffky and Liihrs 

 the bronchial slime of an infected patient contains the virus 

 of the disease, at least in the early stages. In typical cases of 

 infectious pneumonia in which the patients were destroyed on 

 the third or fourth day, in the bronchi was found a quantity 

 of yellow, transparent, viscid fluid which contained no bac- 

 teria. In two experiments on twenty-four colts inoculated 

 with this fluid, by painting it upon the mucosa of the nostrils 

 and in the mouth, the colts became typically ill with infectious 

 pneumonia in twenty-three to forty-two days. Undoubtedly 



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