466 Veterinary Medicine. 



Symptoms. Beside the character of the wound and history of 

 the case, a snake-bite is manifested by great pain and swelling, 

 with a white skin, a violet discoloration for several inches around, 

 and the oozing of a black incoagulable blood from the pricks. 

 The inflammatory swelling may extend so as to involve a large 

 area or an entire limb, and if the patient survives extensive 

 sloughing takes place. The constitutional symptoms may super- 

 vene in from a few minutes to two hours and consist in great 

 prostration and weakness, hurried, difficult, perhaps gasping 

 breathing, thirst, nausea, loss of consciousness, delirium or con- 

 vulsions, with a gradual weakening of the heart, it may be to 

 complete failure. 



The action is evidently exerted largely on the respiratory and 

 cardiac centres in the medulla, but also directly on the blood and 

 especially the red globules, which fail to fulfill their normal 

 respiratory functions. Extensive extravasations of incoagulable 

 blood are found, not only in the wound and vicinity but also in 

 the serous cavities and internal organs. 



The gravity of the bite depends on a variety of causes, such as 

 the size and vigor of the .serpent, and the amount and potency of 

 the venom instilled, the fact of the bite having been the first in a 

 length of time or one of the last in a .series which have expended 

 the available venom and cleaned the teeth, the small size or weak 

 or invalid condition of the animal bitten, and the que.stion of a 

 native or acquired immunity. A bite that would promptly kill a 

 .small animal like a chicken or rabbit, or seriously injure a dog or 

 sheep, would have little more than a temporary local effect on an 

 ox or horse. The pig, like the mongoose, is reputed to be quite 

 immune, and as he thrives on a diet of rattlesnakes, he is availed 

 of to clear up infested localities. A part of the immunity of the 

 pig depends doubtless on the thick layer of subcutaneous fat, 

 which being comparatively Httle vascular, allows of slow absorp- 

 tion only, and the system meanwhile becomes inured to the action 

 of the poison. The same happens to other animals when the bite 

 takes place in a dense, fibrous tissue of little vascularity, A cir- 

 cumscribed inflammation and slough may be the only result. On 

 the contrary, when the venom is discharged directly into a vein it 

 acts promptly on the blood and the nerve centres and too often 

 produces prompt collapse and death. 



