SYMPTOMS. 235 



Surra may be conveniently defined as a specific blood disease 

 of tlie horse, enzootic, marked by general tissue-waste, elevated 

 temperature, extravasations on visible mucous membranes, 

 dropsical swellings ; by possessing the capabihty of being pro- 

 pagated by subcutaneous or intravenous injection and mtro- 

 duction into the stomach of blood containing a parasite, and by 

 the presence of this parasite in the blood during the attack. 



The symptoms of the affection are somewhat varied in 

 character, though some of the more prominent are pretty 

 constant ; fever is present, a yellowish discharge is noticed at 

 the nasal orifices, the submaxillary glands may in some cases be 

 enlarged, and even discharging. In mares there are frequently 

 anasarcous swellings between the fore-legs, in horses in the 

 sheath. The visible mucous membranes are of a sickly yellow 

 colour, and scattered over them are seen petechia3 ; these are 

 said to be most marked at the inner canthus of the eye, and in 

 the female at the vagina. These structural alterations in the 

 mucous membranes are generally continuous, even during de- 

 fervescence of other symptoms. Occasionally appetite may be 

 wanting or deficient, but it is usually retained throughout the 

 disease. Thirst is evinced, the urine is high-coloured, and 

 on examination found to contain albumen. Marasmus is 

 marked, and there would seem to be little relation between 

 this and the amount of food consumed ; for when ample food 

 has been partaken of even until the later stages, the patient 

 almost invariably becomes much emaciated before death. In the 

 earlier stages there is in some cases evidence of loss of power, 

 manifested by stumblings and ineffectual attempts to move the 

 limbs. 



The progress of the disease is of an undulatory character : 

 it usually continues from about seven to ten weeks, when the 

 animal may drop down and expire suddenly ; he may become 

 delirious, and death ensue after a short period ; or the patient 

 may linger on in the lying position for several days, continuing 

 to partake of food, and then to succumb without apparent pain. 

 The pathognomic symptom is of course the presence of the 

 parasite in the blood. 



The revelations of the post-mortem examination are quite 

 in accordance with the manifestations during life. The intes- 

 tinal mucous membrane is of a yellowish colour, and marked 



