GENERAL DISCUSSION OF DISEASE 7 



yards may make a marked diifereiice in the health of the herd. 

 A dry, protected site is always preferable to one in the open 

 or on low, poorly drained soil. The majority of domestic animals 

 need but little shelter, but they do need dry, comfortable quarters 

 during wet, cold weather. 



Faulty feed and faulty methods of feeding are very common 

 causes of diseases of the digestive tract and the nervous system. 

 A change from dry feed to a green, succulent ration is a common 

 cause of acute indigestion in both horses and cattle. The feeding 

 of a heavy ration of grain to horses that are accustomed to exer- 

 cise, during enforced rest may cause liver and kidney disorders. 

 The feeding of spoiled, decomposed feeds may cause serious 

 nervous and intestinal disorders. 



One attach of a certain disease may influence the develop- 

 ment of subsequent attacks of the same, or a different disease. 

 An individual may suffer from an attack of pneumonia that so 

 w^eakens the disease-resisting powers of the lungs as to result in 

 a tubercular infection of these organs. In the horse, one attack 

 of azoturia predisposes it to a second attack. One attack of 

 an infectious disease usually confers immunity against that 

 particular disease. 



Heredity does not play as important a part in the develop- 

 ment of diseases in domestic animals as in tlie human race. A 

 certain family may inherit a predisposition to disease through 

 the faulty or insufficient development of an organ or group of 

 organs. The different species of animals are affected by dis- 

 eases peculiar to that particular species. The horse is the only 

 species that is affected with azoturia. Glanders affects solipeds, 

 while black leg is a disease peculiar to cattle. 



QUESTIONS 



1. What is disease? 



2. How are diseases classified? Give an example of the different classes. 



3. What is a predisposing cause? Exciting cause? 



4. Name the different predisposing and exciting causes of disease. 



