552 DISEASES OF THE HOKSE. 



SO pronounced that the animal falls to tlie ground, and, after a short 

 struggle, succumbs to the disease. In other cases, again, the animal 

 falls to the ground and appears to be suffering from acute pain, 

 struggles violently, sweat covers the body, and respiration is very 

 hurried. The struggles soon exhaust the patient's strength, and for 

 a time it lies quiet; soon, however, the struggles commence again, 

 and this continues until death occurs. In some cases the appetite is 

 voracious. 



Symptoms of the disease as observed in experimentally inoculated 

 ani'mals. — Twenty-four hours after the subcutaneous injection of a 

 small quantity of surra blood, in the great majority of cases, a small 

 circumscribed and somewhat raised swelling is noticed at the seat 

 of the inoculation. After forty-eight hours the tumor has increased 

 in size and is accompanied by some edema ; it presents a certain 

 amount of tension of the parts involved, and is generally tender on 

 manipulation. These conditions continue to increase, until by the 

 fourth day the tumor may measure 3 or 4 inches in one direction by 

 2 or 3 in the other, and raised to the extent of an inch or an inch and 

 a half above the surrounding tissues, or in some cases the tumor pre- 

 sents an almost circular form throughout. It will be also found 

 that, if the tumor be firmly grasped, it is not fixed, but can be lifted 

 up from tlie subcutaneous tissue. According to the nature and 

 amount of the inoculated blood, these symptoms rapidly present them- 

 selves, and either attain a maximum or are retarded until, varying 

 from the fourth to the thirteenth day, the tumor at the seat of inocu- 

 lation will be found to have lost a certain amount of its tension and 

 tenderness. From this date the swelling and edema will gradually 

 begin to grow^ less, until finally, after a period of ten to fourteen days, 

 the only sign left of the former swelling will be slight thickening of 

 the skin over the point of the injection; but at the moment when the 

 tension and tenderness of the parts at the seat of inoculation become 

 suddenly decreased a symptom of the utmost clinical importance 

 takes place, namely, at that moment the parasite of surra enters the 

 blood of the general circulation. 



The temperature on the day of inoculation, and, in fact, for several 

 days afterwards, may remain normal in character, there being only a 

 few degrees difference between the morning and evening observations. 

 In other cases there may be a slight rise from the first evening, and a 

 gradual progressive rise until the swelling at the seat of inoculation 

 shows signs of reduction in size, when the temperature generally 

 takes a decided rise again, and may attain 104° or 105.8° F. This 

 elevation will last a varying period of from tw^o to six days, and on 

 the day following its onset the ordinary symptoms of fever wall be 

 noticed, and in addition there will be petechia^ on the conjunctival 

 membranes, lachrymation, a slight mucous discharge from the nose. 



