Drenching – giving a medicine or liquid preparation by mouth into the stomach of an animal.
Most worm remedies (anthelmintics) are administered by drenching (dosing), as are preparations such as bloat treatments, treatment for diarhhoea and constipation and other medicines.
Incorrect drenching can cause inhalation pneumonia, which is difficult to treat and can prove fatal. It is essential that the farmer always follows manufacturers’ directions when administering any treatment by mouth. Always use the correct dose for the age and size of the animal. If an animal is weak or undernourished smaller doses should be used.
Animals naturally struggle when being drenched or dosed. This may cause the operator to hurry the procedure, resulting in choking of the animal. Often the animal’s head is held so high so that it cannot swallow properly. Liquids should be given slowly, allowing the animal time to swallow. The head should be held firmly but not so high as to impede swallowing. If the animal being treated begins to choke or cough, the procedure must be stopped and the head released. Wait a few minutes for the animal to recover before continuing.


Cattle can be drenched by bottle, large syringe, dosing gun or stomach tube.
1.    The bottle should be strong, with a long neck. The tongue can be pulled forward but not so much as to interfere with its movement and the swallowing reflex. This method can be used when dosing single animals or giving tablets, which are placed on the tongue and washed down with water from a bottle. The same procedure can be followed with a large syringe, but this method is seldom used for cattle.
2.    The dosing gun is used when large numbers of cattle are being drenched eg when administering anthelmintics for worm control. Most dosing guns have a curved end which can be easily hooked into the anima’ls mouth and goes into the side of the mouth avoiding the teeth. With an experienced operator it may not be necessary to hold the head of the animals.
3.    Cattle can also be drenched used a stomach tube known as a Probang. This is a 3m long stiff, smooth tube with a 10-20cm outside diameter. The front end is rounded and a funnel is inserted for poring liquids at the back end. The tube can be used together with a probang gag; a round ball with a hole through the centre which is placed in the animal’s mouth and allows the tube to pass through the hole while preventing the animal from closing its mouth  or biting on the tube. Before use the tube is washed and lubricated with olive oil, raw linseed oil or liquid paraffin. The tube is introduced into the mouth, either through a probang gag, or down the side of the mouth, avoiding the teeth. The tongue should be gently pulled forward. When the tube reaches the larynx the animal will swallow. By gently pushing the tube at exactly the same moment as swallowing it will pass through the pharynx into the oesphagus, another 7-100mm. If the animal does not make the reflex swallowing motion when the tube touches the larynx, it should be gently moved up and down against the larynx until the animal swallows.                                                         
Once past the larynx the tube will go down another 1-1.5m into the rumen. If the tube enters the windpipe by mistake, the animal will cough and the tube will pass easily with no resistance. The tube should be withdrawn and the procedure started again.
When the tube has reached the rumen the operator should check that it is in the correct place by smelling the end of the tube and listening for either air from the lungs or intestinal rumblings from the rumen. When satisfied that the tube is in the rumen, the end of the tube should be lifted to a height above the animal’s throat and the liquid poured into the funnel. Once all the liquid has gone, the tube should be lowered to below the throat and slowly withdrawn.
All remedies given by mouth will go to the rumen (the large stomach) In some cases it may be necessary to get the remedy into the abomasum. (fourth stomach.) Dose the animal with 10% bicarbonate solution – 500g sodium bicarbonate in 5 litres of water. Any liquid or powder that is given 10-15 seconds after this will go to the abomasum.
REF:    Handbook of Stock Diseases; Monnig and Veldman