TETANUS OF THE HORSE 45 



becomes violently excited, and is atfected with spasms of the neck and legs. 

 When a stick is held out the horse will seize it, and may make a feint 

 to attack the person holding it, but, instead of succeeding, the muscular 

 spasm becomes so violent that the horse generally falls, and after a while 

 rises again in an apparently tranquil state. Death usually occurs in less 

 than a week, but, as a matter of common precaution, the horse will be 

 killed as soon as the nature of the disease is ascertained. 



TET.\NUS OF THE HORSE 



Tetanus occupies a somewhat dubious position in the classification of 

 diseases. Formerly it was looked upon as a tonic spasm of the voluntary 

 muscles, resulting from irritation affecting the nerves from an unhealthy 

 wound. The affection was divided into traumatic tetanus, when it was 

 traced to an injury or wound, and idiopathic, when it occurred inde- 

 pendently of any external wound. 



It is somewhat remarkable that the older writers insist very strongly 

 upon the influence of various common causes in the production of this 

 disease. Thus Delatere Blaine, writing in the early part of the present 

 century, refers to tetanus or locked-jaw as a morbid irritation of part 

 or the whole of the nervous system, originating in the brain itself, or 

 ultimately reaching it, according as it is idiopathic or symptomatic. Idio- 

 pathic tetanus, he remarks, is most frequent in the horse, and its causes 

 are, some of them, evident, others, occult. 



In the list of ordinary causes to which he attributes the disease is 

 cold, especially when the body is heated, as in the case of a plunge into 

 a river during a hunting run, or a horse standing still during a check 

 after a severe burst, or the constant dripping of water on to the body 

 from a defective roof of a stable ; also the presence of worms in the alimen- 

 tary canal, especially botts in the stomach. Traumatic or symptomatic 

 tetanus he traces to various external injuries, contusions, lacerations, and 

 wounds made in surgical operations. Wounds of tendinous and liga- 

 mentous parts have always been considered to be particularly dangerous. 



Even twenty years ago tetanus is described as a disease, the general 

 pathology of which is very little known, and writers referred it to an 

 exalted polarity of the nerve-centres, or to a bad condition of the blood, 

 or the effects of cold acting on the sensitive nerves. 



The views above stated, with certain modifications, obtained until 

 Nicolaier, in 1884, discovered that inoculation of mice, rabbits, and guinea- 

 pigs with portions of soils, obtained from streets and from fields, produced 

 symptoms which were considered to be tetanic in their character. In 



