550 BUREAU OF ANIMAL INDUSTKY. 



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

 struggles violent!}', 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 obsei'ved in experhrientally inoculated, 

 animals. — Twenty-four hours after the subcutaneous injection of a 

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

 cumscribed 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 generall}'' tender on manipulation. 

 These conditions continue to increase, until b}- 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 presents an almost 

 circular form throughout. It will be also found that, if the tumor be 

 lirmh' grasped, it is not fixed, but can be lifted up from the subcuta- 

 neous tissue. According to the nature and amount of the inoculated 

 blood, these symptoms rapidly present themselves, and either attain a 

 maximum or are retarded until, varying from the fourth to the thir- 

 teenth day, the tumor at the seat of inoculation 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 linallj', 

 after a period of ten to fourteen days, the onl}' sign- left of the for- 

 mer 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, namel}', 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 generall}^ takes a 

 decided rise again, and ma}' attain 104° or 105.8^ F. This elevation will 

 last a varying period of from two to six daj'^s, and on the day follow- 

 ing its onset the ordinary symptoms of fever will be noticed, and in 

 addition there will be petechise on the conjunctival membranes, lach- 

 rymation, a slight mucous discharge from the nose, and in severe cases 

 some edema of the lower portion of the legs, and perhaps of the sheath 

 in horses. At the termination of the period of fever the temperature 



