TETANUS. 527 



Tlie syiiiptoni of all others to note in a suspected case, is the 

 watchful, horrified, or " hunted " look with which a horse in the first 

 stage of rabies will regard any one who goes near him. The moment 

 this is observed, he should be secured, so that he cannot injure him- 

 self or anyone else, while we are waiting for the confirmation of our 

 suspicion of rabies. 



PREVENTIVE MEASURES.— If we can take the animal in hand 

 shortly after the bite has been inflicted, we should freely cut away 

 the part, or destroy it with a red-hot iron, nitric acid, or lunar 

 caustic. If a bacteriological laboratory be within reach, protective 

 inoculation might be tried. 



AS TREATMENT is of no avail after the symptoms have mani- 

 fested themselves; the only thing to do is to destroy the affected 

 horse. 



Tetanus {Lockjaw) 



is a state of continued contraction of the voluntary muscles,"^ caused 

 by the presence, in the animal system, of poisonous material pro- 

 duced by a ferment which is formed by a specific disease germ (the 

 bacillus spilliformis of Nicolaier). 



NATURE OF THE DISEASE.— The microbes of tetanus are widely dis- 

 tributed over the face of the earth, and grow well in horse dung and on 

 marshy ground. Owing to the fact that they are frequently swallowed along 

 "svith forage, they can often be found in recently expelled dung. The most 

 favourable temperature for their development is about 70° F. They act by 

 means of extremely virulent poisons, which they manufacture, and which 

 cause the terrible and characteristic symptoms of the disease. In fact, a 

 case of tetanus is cis much a case of poisoning as one caused by an overdose 

 of strychnine. The poisonous material of tetanus consists of at least four 

 different kinds of poisons (tetanin, tetanotoxin, spasmotoxin, and hydro^ 

 tetanin), which become fixed in the brain and act on it. The violence of the 

 symptoms, other conditions being equal, appears to be proportionate to the 

 amount of poison received by the patient. 



Carougeau (Cadeac's " Enc^'clopedie Veterinaire ") tells us that in a state of 

 nature, the microbes of tetanus exist in the form of spores which do not 

 manufacture any poison. But if they are introduced into the animal tissues 

 under certain favourable conditions, they go through a form of development 

 and subsequently secrete their toxins, with the result of setting up this 

 disease. If these spores are inoculated by themselves into healthy tissue, 

 they are unable to produce their poisons for the time being, and will in all 

 probability be destroyed by the leucocytes (p. 15). Some of them may, 

 however, remain alive though inactive for even three months or more, and, 

 under conditions favourable to their development, they may subsequently 



*NoTE. — Muscles are divided into voluntary muscles, and involuntary 

 muscles. The former, like tho.-e of the limbs and face, are under the power 

 of the will. The latter, like those of the intestines, heart, and arteries, can 

 perform their duties independently of such control. 



