178 VETERINARY STUDIES 



different outbreaks, and one patient does not usually show all 

 these symptoms. 



This disease is not ordinarily fatal, but it causes very serious 

 losses in the checked milk flow, a prolonged unthrifty condi- 

 tion, and seriously diseased feet. There is a marked fever, 

 highest just before the eruption appears. Active symptoms 

 of the disease last from eight to fourteen days. Disease of 

 the skin around the hoofs often follows the mouth symptoms 

 but the two may occur together. When the disease affects sheep 

 and swine it is apt to involve especially the feet. Many cases 

 are obscure and difficult of recognition. Others are severe 

 and easily recognized. Some show no mouth symptoms and 

 others no foot symptoms. 



There are several diseases that are easily mistaken for foot- 

 and-mouth disease. (See Foot-rot.) 



Vesicular sio'rnatitis affects horses and cattle. The mouth 

 symptoms are similar, but there are no foot or udder lesions 

 and horses are not apt to have foot-and-mouth disease. Hogs 

 and sheep have foot-and-mouth disease, but not vesicular 

 stomatitis. 



Cow pox and sheep pox are of slow development and slow 

 spread and show pustules after the vesicles. They rarely affect 

 any parts except the udder and adjacent skin. 



Dissemination. — The infecting virus may be present in yards, 

 stables, and on the food or feeding utensils on infected farms. 

 Even a road over which diseased animals have passed may be 

 infectious. This disease may be disseminated in an indefinite 

 number of ways, and is recognized as one of the most easily 

 scattered of the infectious diseases. The infectious material 

 is apparently present in the discharge from the vesicles, in the 

 saliva, milk, urine, manure, and perspiration. The infection 

 is probably obtained through the respiratory or digestive 

 organs, usually the latter. 



Prevention. — The prevention of this disease is simply the 

 prevention of infection. Infected premises that have not been 

 disinfected may remain infectious for an undetermined period. 

 Until we have more positive information on this point, we may 

 say that it will hardly be safe to risk exposure in less than a 

 year unless the premises can be thoroughly disinfected. 



This disease spreads rapidly; it causes heavy losses, and is 

 difficult to control after it has become widely scattered. Any 



