GBNBRAI, DISEASES. 1 33 



coma, due generally to a rapid congestion of the brain; to the poisonous 

 effects of the debris of the disintegrated blood corpuscles; to an asphyxia, 

 following congestion of the lungs; or the disease terminates by subsi- 

 dence of the fever, return of the appetite and nutritive functions of the 

 organs, and rapid convalescence; or, in an unfortunately large number 

 of cases, the course of the disease is complicated by local inflammatory 

 troubles, whose gravity is greater in influenza than it is when they oc- 

 cur as sporadic diseases. 



Symptoms. After the exposure of a susceptible horse to infection 

 a period of incubation of from five to seven days elapses, during which 

 the animal seems in perfect health, before any symptom is visible. 

 When the symptoms of influenza develop they may be intense or they 

 may be so moderate as to occasion but little alarm, but the latter con- 

 dition frequently exposes the animal to use and to the danger of the ex- 

 citing causes of complications which would not have happened had the 

 animal been left quietly in its stall in place of being worked. The dis- 

 ease may run its simple course as a specific fever, with alterations of the 

 blood, or it ma}' become at any period complicated by local inflammatory 

 troubles, the gravity of which is augmented by developing in an animal 

 with an impoverished blood and already irritated and rapid circulation 

 and defective nutritive and reparative functions. 



The first symptoms are those of a rapidly developing fever, which 

 becomes intense within a very short period. The animal becomes de- 

 jected and inattentive to surrounding objects; stands with its head down 

 and not back on the halter as in serious lung diseases. It has chills of 

 the flanks, the muscles of the croup, and the muscles of the shoulders, 

 or of the entire bodj', lasting from fifteen to thirty minutes, and fre- 

 quently a grinding of the teeth which warns one that a severe attack 

 may be expected. The hairs become dry and rough and stand on end. 

 The body temperature increases to 104°, 104)4°, and io5°F., or even 

 in severe cases to io7°F. , within the first twelve or eighteen hours. 

 The horse becomes stupid, stands immobile with its head hanging, the 

 ears listless, and it pays but little attention to the surounding attendants 

 or the crack of a whip. The stupor becomes rapidly more marked, the 

 eyes become puffy and swollen with excessive lacrymation, so that the 

 tears run from the internal canthus of the eye over the cheek and may 

 blister the skin in its course. The respiration becomes accelerated to 

 twenty-five or thirty in a minute, and the pulse is quickened to seventy, 

 eighty, or even one hundred, moderate in volume and in force. There is 



