In this tutorial, we will be covering the drenching (deworming) of sheep and lambs. We will cover what drenching is, types of drench, how to safely administer them, and we will cover drench resistance in sheep.

Definition Of Drenching

So, what is drenching sheep? What does it mean?

The term ‘drenching’ can have various meanings, in livestock management it’s used to mean the ‘administering of drug to an animal, usually by force’. Drenching can be applied to most farm animals; it’s not exclusive to sheep. You can buy commercial drenches for cows, calf’s, horses, dogs and other animals.

Types of Drench

Drenches come in two main types: broad spectrum and narrow spectrum.

Broad spectrum drenches are designed to treat a wide range of internal parasites in sheep and lambs. A narrow spectrum drench will treat a restricted range of internal parasite types.

Before you buy your drench, you should conduct a thorough examination of your flock to decide the most suitable drench for your situation.

The time of year, seasons and the condition of your land will also be a factor in your choice as some parasites may be more abundant during certain times of the year.

You might wonder why you might want to use a narrow spectrum drench over a broad spectrum drench that treats many different parasites. Well, there are five good reasons switching to a narrow spectrum drench might be a good idea, they are:

  1. To treat a parasite that’s more common during specific times of the year. (i.e. Liver fluke during the wetter parts of the year).
  2. It might prove more effective and reduce stress on the animal.
  3. It can help combat drench resistance (this is covered later in the article).
  4. A drench that targets a single parasite may be far more effective at its job. This can be desirable when you have a bad infestation of a particular parasite.
  5. It might have a shorter withdrawal period.

Brands of Drench

I did a quick scour of Google and found the follow brands (please note this is not an exhaustive list):

  1. Ivermectin sheep drench (Ivomec)
  2. Cydectin
  3. Noromectin
  4. Triguard
  5. Valbazen
  6. Zolvix
  7. Moxidectin
  8. Nilverm
  9. Pyrimide
  10. Rametin

I wanted to mention some of the various brands of sheep and lamb drenches, because switching brands frequently is one way to help combat drench resistance. So please feel free to use the above list when you are trying to find alternatives brands to use.

There are lots of other brands of drenches available; the list above are the most popular ones. If you want to find more brands of drench, I would recommend that you buy a farming magazine or a publication. Often you can find lots of advertisement in these magazines for drenching products, and some of these will feature the latest drugs and treatments. On our farm we often contact the manufacturers of these drenches and request fact sheets and data sheets. This is a great way of keeping up to date with the latest parasite treatments, and it means you have more choices when you need to switch drenches.

I would also recommend speaking to your local livestock vet and your local farm store about drenching products and brands. They might be able to inform you of a brand or product that’s proving effective in your area.

Sheep Drenching, How it works, How it’s done?

To administer a drench we would use a ‘drench gun’ and give the required dose orally to the sheep or lamb.

This is done forcibly by restraining the sheep and its head, you then place the ‘drench gun nozzle’ into the mouth and dose the sheep.

Depending on the size of your flock, the size of the sheep you are handling and how wild (easy or hard to handle) your sheep are, this might be a job for two people.

You will need to restrain your sheep when performing this task, it might be a good idea to move your animals into a small pen, barn, or a collecting yard.

Check Your Sheep Drench Gun and Equipment

The first thing we need to is to check our equipment. Check that your drench gun is working. It’s also a good idea to calibrate your drench gun and ensure it’s giving the correct dose. Also check the piping and ensure it’s not leaking or blocked.

To calibrate a drenching gun, squirt 5-10 doses into a jug or another measuring container.

Make sure you read the instructions that came with your drench. It will contain important information such as the dosage to weight ratio, withdrawal period, and other precautions that you might have to take.

Most drenching guns have a dial on the side that allows you to set the required dosage.

If you are using an old drench, make sure you check the label to ensure that it hasn’t expired.

Weigh Your Sheep

It’s important that you weigh your sheep and lambs and calculate the correct dosage.

The dosage should be worked out using the heaviest sheep or lamb in your flock.

Giving the wrong dose to the animal can cause problems: too large a dose could potentially kill the animal, too small a dose can encourage drench resistance.

If you are a small flock owner, weighing your animals could be difficult, you might not have access to a set of sheep weighing scales like the one pictured.

I would recommend that you try to either borrow some scales from a local farm, or you build some.

You could try picking up your animals and standing on a set of human scales, this could be difficult if you own larger sheep breed or older animals.

If the weights in your flock differ greatly, split your flock into several weight categories, giving each category its required dosage.

Prepare Your Sheep Handling Equipment

We start the process on our farm by bringing the sheep in to our collecting yard. This is a good time to inspect your flock members to see whether any animals have other problems. Look for any animals that are limping, itching, or have mucky backsides.

Animals found limping or lame might need a foot trim, sheep with mucky backsides could have worm problems and possibly be the victims of fly strike.

How to Drench Sheep and Lambs


Sheep jammed into a sheep dip and handling area
Jamming the sheep into a small space makes them easier to dose. You can also do the job faster


deworming sheep
Sticking your finger in their mouth can cause a nasty bite. Wear a thick glove on one hand and try to keep your hand to the back of the sheep’s mouth past their teeth


deworming a lamb
If their mouths are open during the dosing it can cause the drench to spill


Deworming tutorial
This is the ideal way to dose a lamb, arm under their neck and gun inserted into the side of the mouth


  1. Make sure you thoroughly shake the drenching container and ensure the contents are well mixed.
  2. Check you have the right dose set on the gun.
  3. Restrain your sheep. Place your hand under the animal’s neck and hold it firmly. I find this operation easiest when you are stood towards the back of the animal.
  4. Insert the drenching nozzle into the sheep or lambs mouth from the side. Make sure the nozzle is above the tong whilst ensuring you keep a firm grip of the animals’ mouth.
  5. Remove the gun from the mouth whist still keeping a firm grip of the animal mouth and head. You need to keep hold of the animal mouth until it’s swallowed the dose. This only usually takes a few seconds. If you don’t do this it could dribble out of the mouth, or the animal could spit it out.
  6. Once you have finished dosing your flock, clean your equipment. Rinse the gun and pipe out with warm water. Don’t use soap as this can damage the seal in the gun.
  7. Make sure you make a note in your diary of when the drench was applied and the withdrawal period.
  8. Safely store your unused drench whilst ensuring it’s out of direct sunlight.

Drenching Tips

When drenching do not pull the animals back severely – it won’t be able to swallow properly.

Don’t put the nozzle through the front teeth as it’s not designed to be used this way.

Don’t jam the gun down the back of sheep throat. You might shoot the liquid into the animal lungs.

Be careful not to break any teeth. Broken teeth inhibit a sheep’s ability to graze therefore affecting their ability to put on weight.

Once you have drenched your animals, it can be a good idea to place them on clean pasture if it’s available. This can help minimize the re-infestation rate.

How often should you Drench?

There are no rules to drenching. It will vary from flock to flock and farm to farm. A lot depends on where you live, time of year, your local conditions, worm burden, and how widespread other parasites are in your area.

Ideally, you want to minimize the occasions when you have to use a drench – this can reduce your costs, and help prevent drench resistance.

Consult your local livestock veterinarian about your drenching program. They might be able to advise you as they will have a good idea of the localized threats around your area.

Sometimes it’s worth performing a worm test on your farm. This can sometimes help decide how often you should drench your flock. See your vet about how to perform such a test

Minimizing Drench Resistance

‘Drench resistance’ refers to the problem of parasites developing a resistance to particular drench drugs and chemicals. This starts to render the drench less effective over time. And given enough time, it can possibly render some drugs useless. It’s a problem that every country and its sheep farmers face.

Some precautions can be taken to minimize drench resistance build up, these are:

  1. Try to minimize the frequency of drench treatments: try to take a proactive approach in your fight against parasites (i.e. try rotating your flock between pastures; eliminate wet areas where liver fluke snails might be present, etc).
  2. Rotate the brands and drugs used in your drenching program
  3. Ensure you administer the correct dose to the animal. Do not under-dose your animals, this will not effectively kill parasites. Under-dosing allows the parasite to become more ‘used to’ and ‘resistance to’ the active drugs in the drench solution. Also, try to ensure the animal swallows all the drench and it doesn’t spit it out or it dribbles out.
  4. Don’t use an expired drench.
  5. Try an organic drench solution.

I would advise that you speak with your local vet about drench resistance in your area, they might be able to advise you on the brands to use or avoid.


That concludes our look at drenching sheep, or deworming. You should now have a better idea of what a drench is, how to apply it, and the precautions you should take. I hope this tutorial highlights the importance of this task for effective flock management and sheep health. I hope it has shown you that a good drenching program needs be planned and it shouldn’t remain a static job where the things are not changed.

Have you any thoughts on drenching? What treatments do you find in effective in your area? Why not share your thoughts in the comments below.


    • Thanks Andrew. I’m really happy you find these posts helpful. They take a lot of time, effort and research to put together so it’s great when i get feedback like yours.
      In the future we’re going to be combining video footage with these posts making them more in depth and clearer. So that’s something to look forward to.
      Over the coming weeks I’ll be writing a few chicken and poultry posts, but after these it’ll be back to the sheep posts.
      Have a great day


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