510 DISEASES OP THE HOBSE. 



VACCINATION. 



In recent years vaccination for the prevention of certain infectious 

 diseases has been successfully developed, and without a doubt the 

 future has a great deal in store for this phase of prevention. At the 

 present time vaccination has been found effective against blackleg, 

 hog cholera, anthrax, lockjaw, strangles, rabies, hemorrhagic sep- 

 ticemia, white scours, etc. It is always essential, of course, that the 

 products used for the vaccination be pure and potent; also they 

 should be employed only with the advice of competent authorities 

 and with proper care. The biological products prepared for the 

 cure and prevention of infections are prepared by manufacturers 

 who, in order to conduct an interstate business, are required to 

 obtain a license from the United States Department of Agriculture 

 for the manufacture of such preparations. 



Since July 1, 1913, the Department of Agriculture, by an act of 

 Congress of March 4, 1913, has had control of the manufacture of 

 biological products for the treatment of domestic animals. The 

 numerous complaints which were received from time to time rela- 

 tive to the impotency of some of the preparations, and also the fact 

 that in some instances the use of the products were directly respon- 

 sible in causing outbreaks of disease, made the necessity for such 

 control obvious. This supervision is no doubt of far-reaching im- 

 portance, as it assures the users that the preparations are reliable. 



INFLUENZA. 



Synonyms. — Pinkeye, typhoid fever, epizooty, epihippic fever, hepatic fever, 

 bilious fever, etc.; flSvre typhoide, grippe (French) ; Pferdestaupe (German) ; 

 gastro-enterltis of Vatel and d'Arboval ; febris erysipelatodes, Zundel ; typhus 

 of Delafond. 



Definition. — The term influenza is applied to a febrile, contagious, 

 infectious disease of horses, which is characterized by a blood infec- 

 tion, with inflammation of the mucous membranes, which frequently 

 involves the lungs. Inflammatory complications also occur in the 

 form of swellings of the subcutis, tendons, and tendinous sheaths 

 and laminae of the feet. The causative agent has not been satis- 

 factorily established. One attack usually protects the animal from 

 future ones of the same disease, but not always. An apparently com- 

 plete recovery is sometimes followed by serious sequelae of the ner- 

 vous and blood-vessel systems. Under certain conditions of the at- 

 mosphere or from unknown causes, the disease is very liable to as- 

 sume an epizootic form, with tendency to complications of especial 

 organs, as, at one period, the lungs, at another the intestines, etc. 



The first description of influenza is given by Laurentius Rusius 

 in 1301, when it spread over a considerable portion of Italy, causing 



