40 VETERINARY STUDIES 



tion, for example — and that these changes interfere with normal 

 function. 



Posterior paralysis of swine is of many types, due to several 

 different causes and characterized by partial or complete motor 

 paralysis of the hind quarters. 



Milk fever (poorly named) is a common disorder of cows at 

 calving time, characterized by both motor and sensory paralysis, 

 loss of consciousness, etc. (See Lecture XLIX.) Treated by 

 pumping the udder full of air and giving hypodennic stimu- 

 lants when necessary. 



Stringhalt, or spring halt, is a peculiar affection usually of 

 one or both hind legs, characterized by a sudden jerking of the 

 limb upward. Treatment by a veterinary surgical operation 

 cures in some cases. 



Rahies (hydrophobia) is a serious disorder of the nervous sys- 

 tem, usually produced by inoculation from the bite of an affected 

 animal— usually a dog— the virus being in the saliva. This is 

 characterized in the dog by unnatural affection at first, then by 

 a tendency to run away from home, biting animals or people 

 en route, then paralysis of the lower jaw and tongue, hoarse, 

 unnatural bark, and death. Some cases are mild, quiet, and 

 deceptive. Treatment of bitten person by prompt vaccination 

 is a reasonably certain preventive. Animals that have been 

 bitten should be killed or securely confined for a month or more. 



Facial paralysis is usually due to paralysis of the 7th cranial 

 nerve, and is indicated by a drawing of the lips toward the 

 sound side. 



Tetanus (lock jaw) affects various domestic animals and 

 people. It is caused by inoculation with a bacillus common in 

 garden earth, and is characterized by tense, persistent contrac- 

 tion of the voluntary muscles, including those of the jaws; by 

 a spasmodic movement over the eyeball of a membrane often 

 called the haw or third eyelid (properly the nectitating mem- 

 brane). It is frequently fatal, but can usually be prevented by 

 prompt injection of large doses of anti-tetanic serum soon after 

 an injury, for example a nail puncture in the foot. 



Over heat, often called sunstroke, is either an exhaustion of 

 the temperature regulating nerve machinery or an overwhelm- 

 ing of the nervous system by an excessive accumulation of heat 

 within the body. It is most apt to affect the animal that is out 

 of condition for heat and exercise, or the hoi-se that has been 



