DISEASES OF THE NERVOUS SYSTEM. 241 



one-half grain doses, subcutaneously, has given as much satisfaction 

 as any other drug. After purging the animal the treatment is mostly 

 symptomatic. Intestinal disinfectants, particularly calomel, salol, 

 and salicylic acid, have been recommended, and mild, antiseptic 

 mouth washes are advisable. Antipyretics are of doubtful value, as 

 better results are obtained, if the temperature is high, by copious 

 cold-water injections. An ice pack applied to the head is beneficial 

 in case of marked psychic disturbance. One-ounce doses of chloral 

 hydrate per rectum should be given if the patient is violent or if 

 muscular spasms are severe. If the temperature becomes subnormal, 

 the animal should be warmly blanketed, and if much weakness is 

 shown this should be combated with stimulants, such as strychnin, 

 camphor, alcohol, atropin, or aromatic spirits of ammonia. Early 

 in the disease urotropin (hexamethylenamin) in doses of 25 grains, 

 dissolved in water and given by the mouth every two hours, ap- 

 peared to have been responsible for the recovery of some cases of 

 the malady. During convalescence tonic treatment is indicated. 



Hygienic measures needful. — ^Whenever this disease appears in a 

 stable all the animals should be removed as soon as possible. They 

 should be provided with clean, well-ventilated, and well-drained 

 stables, and each animal should receive a laxative and be fed feed 

 and given water from a new, clean source. The abandoned stable 

 should be thoroughly cleansed from all waste matters, receive a coat 

 of whitewash containing 4 ounces of carbolic acid to the gallon of 

 water and should have time to dry thoroughly before the horses are 

 replaced. A complete change of feed is of the very greatest im- 

 portance on account of the belief that the cause resides in diseased 

 grain, hay, and grass. 



TETANUS, OR LOCKJAW. 



This disease is characterized by spasms affecting the muscles of 

 the face, neck, body, and limbs and of all muscles supplied by the 

 cerebrospinal nerves. The spasms or muscular contractions are rigid 

 and persistent, yet mixed with occasional more intense contractions 

 of convulsive violence. 



Causes. — This disease is caused by a bacillus that is often found in 

 the soil, in manure, and in dust. This germ forms spores at the end 

 of the organism and grows only in the absence of oxygen. It pro- 

 duces a powerful nerve poison, which causes the symptoms of tetanus. 

 The germ itself multiplies at the point where it is introduced, but its 

 poison is absorbed and is carried by the blood to all parts of the body, 

 and thus the nervous system is poisoned. Deep wounds infected by 

 this germ are more dangerous than superficial wounds, because in 

 them the germ is more remote from the oxygen of the air. Hence, 



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