192 TETANUS 



der is usually distended with urine and its mucous membrane 

 is often sprinkled with ecchymoses. The digestive tract may 

 show areas of congestion and ecchymoses. 



The course of the disease varies in different species and in 

 different individuals of the same species. In the horse it may 

 last for two or three days only or it may continue for several 

 weeks. In cattle the course is usually less rapid, but it rarely 

 runs longer than two weeks. In sheep it usually terminates 

 fatally within a week and often in two or three days. 



§ 148. DifTerential diagnosis. Tetanus, while possess- 

 ing quite characteristic symptoms, may be mistaken for a 

 number of other affections or specific diseases. Among those 

 which should receive special attention are cerebro- spinal men- 

 ingitis and rabies (for the symptoms and lesions see those dis- 

 eases). Rheumatism, eclampsia, catalepsy, convulsions in the 

 newly born and pyaemic polyarthritis in lambs and foals. 



The symptoms of tetanus which are perhaps the most 

 diagnostic are (i) the continuous tonic spasms of different 

 groups of muscles, (2) the apparent clearness of mind, (if we 

 may attribute such a quality to animals) and (3) the absence 

 of fever in the beginning of the S5miptoms. The general atti- 

 tude of the animal is also of much value. If the infected 

 wound can be found it is often possible to obtain coverglass 

 preparations in which the tetanus bacilli can be found. Nega- 

 tive results are in this case not to be considered as final for it 

 is practically impossible to make these examinations suiSci- 

 ently thorough to be sure of the absence of these bacilli, if 

 they are not found. If they are found the diagnosis ma}- be 

 considered as positive. 



In poisoning with strychnine, there are symptoms which 

 at first may be more confusing. This form of poisoning 

 usually occurs in dogs where tetanus is rare and again in 

 strychnine poisoning the suddenness of the attack, the rapidity 

 of the cour.se and the increased reflex irritability are valuable 

 diagnostic features. In differentiating tetanus from other 

 affections as those in the newly born, the bacteriological exam- 

 ination of preparations made from the end of the umbilicus may 

 be of much assistance. 



