DISEASES OF THE HORSE 49 



LOCK-JAW 

 (Tetanus) 



Cause : The bacilli of Tetanus are widely distributed 

 and can be found in practically every part of the globe. 

 Their favorite place of production, however, is in barn 

 yards and marshy ground. They are frequently swal- 

 lowed by stock along with forage, and can often be found 

 in recently expelled feces. The most favorable temper- 

 ature for their development is about 70° F. They act 

 by means of extremely virulent poisons which they pro- 

 duce, and which causes the terrible symptoms that are 

 characteristic of the disease. 



Symptoms : The muscles of expression are usually 

 the first brought under the continual spasm of tetanus, 

 and when thus affected give the face of the animal a 

 pinched and drawn-in appearance. The other muscles 

 of the head and those of the neck are next attacked. The 

 mouth is closed, the nose poked out, the head elevated. 

 The muscles of breathing, and those of the limbs, be- 

 come contracted so that the neck is hollowed, and the 

 tail is raised, the horse stands with outstretched limbs. 

 The animal shows great stiffness or rigidity in attempted 

 movements. The eyes are sunken, and when startled 

 or excited, the breathing is quickened and the flanks 

 have a wrinkled or corrugated appearance. Death may 

 quickly occur from continuous spasms of the muscles of 

 the throat. Another sign is the flying up of the accessory 

 eyelid when the animal is excited. 



Treatment : If noticed in its first stages, and if the 

 animal is able to eat, secure the services of an accom- 

 plished Veterinarian and insist on the use of fresh vac- 

 cine. This disease is almost impossible to cure, and 

 about ninety per cent die. 



