DISEASES OF ANIMALS 



117 



Rabies occurs in cattle as well as in 

 other domestic animals, being due usu- 

 ally to the bite of a rabid dog. (See 

 under Diseases of Dogs.) 



Cowpox, also known as variola, is an 

 infectious disease of cattle characterized 

 by fever, falling off in the milk yield 

 and the appearance of pustules on the 

 teats and udder. The disease ordinarily 

 runs a harmless course and is quite prev- 

 alent, especially in the eastern states. 

 It is not transmitted, except by contact. 

 A similar disease affects horses and 

 sheep. As should be well known, the 

 virus obtained from the pustules of cow- 

 pox is used in vaccinating man against 

 smallpox. This virus produces a mild 

 form of the disease, from which man 

 recovers in a few weeks and is then 

 immune to smallpox. If it becomes nec- 

 essary to treat the teats and udders of 

 cows, good results may be obtained from 

 the use of some antiseptic wash or oint- 

 ment such as carbolized vaseline or iodo- 

 form ointment. 



Actinomycosis, also called lumpy jaw, 

 big jaw and wooden tongue is an infec- 

 tious disease due to the ray fungus. This 

 fungus causes local tumors in the bones 

 and other tissues. The disease is com- 

 mon in cattle, but affects also the pig, 

 sheep, horse, deer and man. The pres- 

 ence of the fungus may be detected by 

 the naked eye in the form of minute 

 yellow spots. The most common loca- 

 tion of the disease in cattle is in the 

 bones of the upper and lower jaw, the 

 salivary glands and the throat. Tumors 

 may also be found on the tongue, and 

 the disease is occasionally observed in 

 the lungs and intestines, where it may 

 sometimes be mistaken for tuberculosis. 

 Big jaw is apparently contracted in 

 minute skin wounds or through dis- 

 eased and decaying teeth. The fact that 

 most cases appear in the head indicates 

 an infection through the teeth or mu- 

 cous membrane of the mouth. The first 

 treatment adopted for this disease was 

 the removal of the tumors and cauteriz- 

 ing with hot irons or chemicals. Sub- 

 sequently, it was found that iodide of 

 potash in eight to twelve-gram doses re- 

 peated daily for five or six days and 

 again for a similar period after an 

 interval of two or three days gives com- 

 plete success. The drug should be ad- 

 ministered in water in the form of a 

 drench. It is quite uncertain whether 

 this disease is directly communicated to 



man in eating the meat of cattle affected 

 with lumpy jaw. Where the head alone 

 is affected the meat is not condemned. 

 A generalized case of lumpy jaw, how- 

 ever, is sufficient to cause condemna- 

 tion. 



Anthrax j s m0 st common in cattle 

 and sheep, but also affects other domes- 

 tic animals and may be transmitted to 

 man. (See under Diseases of the Horse.) 



Blackleg, also known as quarter-ill, 

 black quarter, symptomatic anthrax and 

 charbon in the southern states, is a 

 highly infectious disease of young cat- 

 tle _ characterized by external swellings 

 which give forth a crackling sound when 

 stroked. Cattle are most susceptible be- 

 tween the ages of six months and two 

 years. The disease also affects sheep 

 and goats, but other domestic animals, 

 as well as man are immune. Blackleg 

 ordinarily runs a rapid and fatal course. 

 The dry spores of the blackleg bacillus 

 may be carried in hay or other feed and 

 may thus affect cattle, but the bacillus 

 ordinarily gains entrance to the body 

 through wounds in the skin, mouth 

 tongue or throat. Affected animals rap- 

 idly lose weight, become dull and show 

 a high fever. A stiffness or lameness 

 of the legs takes place as the result of 

 muscular swellings and death occurs in 

 one and a half days after the appear- 

 ance of the first symptoms. Blackleg 

 may be readily distinguished from 

 anthrax by the presence of crackling 

 tumors, which contain gas. In anthrax 

 the spleen is greatly enlarged and the 

 blood does not clot readily, while in 

 backleg the spleen is not affected and 

 the blood clots within the usual time. 

 Treatment for blackleg is not to be rec- 

 ommended, since it is of little avail. 

 Excellent results, however, have at- 

 tended the use of vaccination in pre- 

 venting the development of this disease. 

 Vaccine for this purpose is produced by 

 the Bureau of Animal Industry and has 

 been distributed to the extent of several 

 million doses. The reports received from 

 different parts of the country indicate 

 it as a practical and efficient means of 

 controlling the disease. Throughout 

 the blackleg areas in this country the 

 amount of infection is usually from 10 

 to 20 per cent with death in almost all 

 cases. After the use of blackleg vac- 

 cine, however, the loss from this disease 

 is reduced to less than 1 per cent, 



