Casting animals: Horses

The following methods are employed for casting horses: 
(a) the use of side lines (single as well as double)
(b) the use of hobbles
Single side lines: Cotton web is ideal for a good side line. A slipping knot is made at the pastern. The side line is then passed between the forelegs, and the free end taken round the neck, brought up over the shoulder to the near side, and a knot applied near the elbow drawing the hind leg a little bit forward.
Double side lines: A slipping knot is made at the near hind pastern, the knot being on the outside. The side line is then passed between the forelegs and given a turn. The free end is then passed under the previous turn of the side line and passed over the shoulder onto the off side. The side line is then wound round the off forelimb in a similar fashion as was done on the near side, and then it is passed around the pastern and a knot tied on the outside. Both the hind legs are brought slightly forward during the operations.
Hobbles: Hobbles are used for heavy draught horses. A set of four hobbles with a chain about 3 m long is used. Attached to this is an approximately 5 m long rope with a spring "D"-catch. One of the hobbles, the "master hobble", has an arrangement by which the chain is screwed on to it.
Hobbles (Courtesy:
The hobbles should first be laid out, each in its right position, and then placed on the horse. If the horse is to be east on the right side, the master hobble is attached to the left fore-pastern. A rope is slipped round the upper arm of the foreleg which is to be uppermost, and passed over the withers to the assistant standing on the other side whose task is to pull the animal on to the required side. As soon as the hobbles are adjusted, the person at the head backs the horse quickly. At the same time, the hobbles are pulled together, and the person holding the rope over the withers pulls the horse over. As soon as the operation is finished, the hobbles must be taken off with the horse still lying down. 
Use of Tranquilizers before casting: 
Very vicious and highly nervous large animals can be calmed before casting by administering tranquilizers such as "Largactal" (tm) or other chlorpromazine compounds, or depressants such as chloral hydrate or barbiturates. The drugs minimize struggling and make application of ropes and appliances easier. The narcosis or sub-narcosis attained should not be so great as to leave the animal weary for a long time.
For cattle and buffalo, chloral hydrate is most common drug used since it is cheap, efficient and can be easily administered orally as a drench or electuary in drinking water. The dose varies from 15 - 45 g for cattle and 2 - 4 g for sheep, depending upon the size of animal. The animal should be fasted for 18 - 24 hours before administering the drug, which is done about one hour before the actual handling of the animal.
A presentation about casting horses for different purposes can be viewed here.