OFFICIAL PREPAKATIONS 79 



Haustus, pi. Havstus. — Drenches are extemporaneous 

 fluid mixtures, intended for immediate use as a single dose. 



Soluble substances are best given in solution to obtain 

 the most rapid results, unless irritating. Even then they 

 may be preferable when sufficiently diluted with water and 

 demulcents. Insoluble drugs may at times be given to 

 advantage in a mixture rather than in the form of a ball or 

 powder. Most official fluid preparations require dilution 

 before administration, but for convenience small doses of 

 tinctures and fluid extracts are dropped upon the tongue of 

 horses unless the preparations are exceptionally acrid. 

 Drenches are particularly applicable for cattle and sheep, as 

 solids are not quickly absorbed in their capacious digestive 

 apparatus, and drenches are given them with ease. 



The amount of liquid conveniently administered to 

 horses is from one to two pints ; to dogs, from two to four 

 ounces ; to sheep, six to eight ounces. Cattle take readily 

 unlimited quantities. Care should be observed that drenches 

 are so diluted as to be harmless to the mucous membrane, 

 and, if containing insoluble drugs, that these be held in 

 suspension by a suitable vehicle or thoroughly shaken before 

 using. Drenches are given to horses by raising their head 

 with a " twitch " on the nose, held by an assistant, or by a 

 rope leading from the halter to a ring overhead. A horse 

 may be first backed into a narrow stall. The neck of the 

 bottle (which should properly be made of horn or tin) con- 

 taining the drench, being introduced and held in the right 

 hand of the operator between the outside of the back teeth 

 and the inside of the cheek of the patient, the left hand is 

 used to steady the nose of the animal, but the nostrils should 

 not be obstructed. 



In giving drenches to cattle the operator stands on their 

 left and passes his right arm between the horns over the 

 poll and down in front of the face, grasping the nasal septum 

 between the thumb and forefinger. The neck of the bottle 

 is then thrust with the left hand into the animal's mouth. 

 Dogs are given drenches with the aid of an assistant, who 



