If you think that your sheep may be dealing with worms and it isn’t shearing season, collect a sample of their stool and bring it to your vet for testing. They’ll be able to tell you whether or not you should drench.
Make sure that the drench gun is clean, free of leaks, and put together properly. Twisted tubes can result in harmful air bubbles. Check for leaks by placing your finger over the nozzle of the empty gun and squeezing the trigger.
Do not base dosage on a smaller sheep. Using a smaller dose than necessary can cause the parasites to become resistant to the drench, making the medication less effective. On the other hand, giving sheep a dramatically larger dosage than necessary could make the animal sick and may result in its death. If the sheep in your flock vary greatly in size, split the group into different sections based on weight. Weigh the largest sheep in each group and calculate a different dosage for each group based on that.
Even if you’ve used a certain drench before, read the instructions anyway. Dosage rates do change over time, so it’s worth double checking every time you drench.
If you aren’t sure whether or not to withhold food, check the instructions on your drench. If you’re still unclear, talk to your vet.
It’s important to keep track of which sheep have been drenched and which haven’t throughout this process.
Most drench guns have a dial on the side that allows you to set the dosage. Check this dial in between each drench to make sure that it remains set at the correct amount.
Even though tilting the head can help you administer the drench, keep in mind that the head should be mostly horizontal. Allowing the sheep’s head to tilt too far to one side can cause some of the drench to slip out of the mouth, resulting in improper dosage. Pulling the head back too far can prevent the sheep from swallowing. Do not put your thumb or fingers in the mouth, even if doing so would help you steady the sheep. The sheep will probably bite you if it senses your fingers near or inside its mouth.
Stay situated behind the sheep as you do this—sheep will instinctively run forward, and it’s much easier to control them if you hold their chin from behind them. Pushing the nozzle too far back into the sheep’s mouth can puncture the tissue at the back of the throat, which can be fatal. Be sure to rest the tip of the nozzle on the back of the tongue, and do not press into the back of the throat.
Be gentle yet firm while delivering the dose to each sheep. If you are too aggressive, you may damage the back of the throat, break teeth, or get the drench into the sheep’s lungs.
If you release the sheep before it swallows the dose, the drench may spill out of the mouth or the sheep could spit some of it out.
Be sure to check the expiration date before using the drench again.
If your sheep are still sickly after a few days, the problem may be something besides worms. In that case, talk to your vet about your next steps. [21] X Research source
