TETANUS. LOCKJAW 613 



be absent. As the disease progresses the animal shows more 

 pain by howling, crying, or groaning. The muscles around 

 the head and face often show marked twitching, which may 

 be periodical or constant. The nervous system is affected as 

 is shown by increased reflex excitability, paralysis of the 

 pharynx and larynx, and increased muscular sensitiveness. 

 There is marked dyspnea. The temperature is usually normal 

 or subnormal ; toward the end the subnormal temperature is 

 very marked. The animal usually dies in about thirty-six 

 to forty hours. 



Diagnosis. There might be some difficulty in establishing 

 an accurate diagnosis. However, the symptoms, which are 

 quite constant, and the rapid, fatal course, would assist. 



Differential Diagnosis. In the dog and cat it is necessary 

 to distinguish this disease from rabies. The chief points of 

 difference are the following: (a) Rabies (furious) is charac- 

 terized by symptoms of rage or fury, aggressiveness; in dumb 

 rabies by paralysis of the lower jaw. Both are absent in 

 bulbar paralysis, (b) The saliva in rabies is highly infectious 

 while in this disease it is non-infectious, (c) The period of 

 incubation is usually from two to nine days, while in rabies, 

 although variable, it is much longer. On account of its rapid 

 course, it might easily be mistaken for some acute poisoning. 

 Should the symptom of itching and irritation be absent a 

 differentiation would be quite difficult. In such cases experi- 

 mental inoculation with the blood of the affected animal into 

 healthy ones will assist. Frequently, a number of animals 

 in a neighborhood will become infected at the same time, the 

 disease appearing in the form of an enzootic. 



Prognosis. Very unfavorable. The majority of cases die. 



Treatment. Treatment is unsatisfactory. Antiseptics for 

 the digestive tract may be tried. Thorough disinfection is 

 necessary in order to check the disease. All dead animals 

 should be burned or buried in lime to destroy the virus. 



TETANUS. LOCKJAW. 



Definition. An acute, infectious disease, characterized by 

 involvement of the nervous system, resulting in spasmodic 



