INFLUENZA 141 



INFLUENZA 



There is no one disease to which horses are subject 

 that can present a greater variety of clinical pictures than 

 this one. Influenza is essentially a contagious catarrhal 

 fever. It is presumed to be due to infection with a 

 microorganism of doubtful identity, and is presumably 

 the equine type of "La Grippe." The characteristics 

 of influenza are very similar in equine patients to those 

 in human beings. They are fever, great depression, 

 catarrhal changes in mucous and synovial membranes, 

 and frequently grave complications such as pneumonia, 

 and involvement of various organs in uncertain degree. 



It is a question whether there is such a thing as a 

 typical attack of influenza. The disease rarely follows a 

 typical course ; irregular developments are the rule rather 

 than the exception. While affection of a distinct organ 

 usually occurs in a typical form, it is only rarely that 

 the same parts of the anatomy are invaded in a series of 

 cases. "When regular involvement of an organ, or a set 

 of organs, occurs in an outbreak of influenza, the prac- 

 titioner is very apt to be led astray in his diagnosis. The 

 best example of this sort of an occurrence we have in 

 the name "pink eye." This is nothing more than a 

 panophthalmitis, now and then a mere conjunctivitis, 

 being presented in the form of a localized influenza in- 

 fection. Not many years ago ' ' pink eye ' ' was considered 

 as a separate and distinct disease of horses. In like man- 

 ner, we have witnessed outbreaks the cases of which were 

 characterised by enteric symptoms, and in which the 

 practitioner usually failed to see influenza infection. The 

 most disastrous outbreak of this form of the disease 

 occurred in the late '90 's. 



Quite regular involvement of other parts of the anat- 

 omy have been observed in various epizootics of this dis- 



