492 BUREAU OF ANIMAL INDUSTRY. 



on the blood. Hence blood-letting should be practiced only in full- 

 blooded, well-nourished animals and in the earh' stages of the disease. 

 Cathartics act by drawing off a large quantitN' of fluid from the 

 blood through the intestines, and have the advantage over the last 

 remed}" of removing only the watery and not the formed elements 

 from the circulation. The blood cells remain, leaving the blood as 

 rich as it was before. Again, the glands of the intestines are stimu- 

 lated to excrete much waste matter and other deleterious material 

 which may be acting as a poison in the blood. 



Diuretics operate through the kidne3\s in the same way. 



DiajyTioretics aid depletion of the blood by pouring water in the form 

 of sweat from the surface of the skin and stimulating the discharge of 

 waste material out of its glands, which has the same effect on the blood 

 pressure. 



Antipyretics are remedies to reduce the temperature. This may be 

 accomplished b}^ depressing the center in the brain that controls heat 

 production. Some coal-tar products are ver}^ effective in this way 

 but they have the disadvantage of depressing the heart, which should 

 always be kept as strong as possible. If they are used it must be with 

 knowledge of this fact and it is well to give heart tonics or stimulants 

 with them. The temperature of the body may be lowered by cold 

 packs or by showering with cold water. This is a most usefid pro- 

 cedure in many diseases. 



Depressants are drugs which act on the heart. The}' slow or weaken 

 the action of this organ and reduce the quantity and force of the cur- 

 rent of the blood which is carried to the point of local disease; they 

 lessen the vitality of the animal, and for this reason are now used much 

 less than formerly. 



Anodynes quiet the nervous system. Pain in the horse, as in the 

 man, is one of the important factors in the production of fever, and 

 the dulling of the former often prevents, or at least reduces, the latter. 

 Anodynes produce sleep, so as to rest the patient and allow recupera- 

 tion for the succeeding struggle of the vitality of the animal against 

 the exhausting drain of the disease. 



The diet of an animal suffering from acute iuitlannnation is a factor 

 of the greatest importance. An overloaded circulation can be starved 

 to a reduced quantity and to a les^ rich quality of blood by reducing 

 the quantity of food given to the patient. Foods of easj^ digestion do 

 not tire the alread}- fatigued organs of an animal with a torpid diges- 

 tive system. Nourishment will be taken by a suffering brute in the 

 form of slops and cooling drinks where it would be totallj^ refused if 

 offered in its ordinary form, as hard oats or dry hay, requiring the 

 labor of grinding between the teeth and swallowing b}" the weakened 

 muscles of the jaws and throat. 



Tonics and stiimdants are remedies which are used to meet special 

 indications, as in the case of a feeble heart, and which enter into the 



