6 The Diseases of Animals 



before receiving grain. Bulky food, or that con- 

 taining a large amount of indigestible substance, 

 should be fed to horses sparingly. Cattle and sheep 

 are not so easily injured by it, since they have greater 

 digestive capacity. Musty or dusty hay fed to horses 

 is likely to produce indigestion or heaves ; and it is 

 often a source of much trouble to other animals. 

 Moldy and wormy food is often the cause of a 

 serious brain disease among horses and mules ; and 

 moldy ensilage sometimes poisons cattle. 



Grasses or grain often contain ergot, a parasitic 

 fungus, which shows itself among the healthy grains 

 as long black kernels. This fungus most frequently 

 attacks rye and related wild grains. The feeding of 

 this " spurred rye " to animals is likely to produce in 

 them a disease called ergotism. In this disease the 

 blood-vessels of the extremities contract to such an 

 extent that the feet of the aflicted animals frequently 

 slough off, and sometimes, also, the tails. Corn-smut, 

 so far as known, does not cause disease. If fed in 

 large quantities, however, it is likely to produce indi- 

 gestion . 



Underfeeding is a result of insufficient food, or 

 of food that is not sufficiently nutritious and diges- 

 tible. As a result of underfeeding, animals fall away 

 in flesh, become "hidebound," and the coat takes on 

 a harsh and lusterless appearance, which is caused by 

 the absorption of fat from beneath the skin. A sim- 

 ilar appearance may also be produced by disease. In 

 bringing underfed animals back into condition, care 

 must be taken not to overfeed. It is best to increase 



