Dosing gun calibration

Under dosing is one of the contributing factors to the development of anthelmintic resistance. It is important that we ensure the dosing equipment we are using is delivering the correct amount of dose that is required. Damian Costello, Teagasc Sheep Specialist has some advice.

You will need to set the dosing gun to the indicated amount of product that you require on a given day. Use the actual product you intend to use when calibrating the gun and not for example water as viscosities will vary. You will also need a suitable container that will allow you to accurately measure it e.g. graduated cylinders, sample tubes or 60ml syringes.

Allow the dosing gun to fill removing any excess air from it. Once you are setup, dispense the dose into the container ensuring the plunger is fully depressed and released each time. It’s important you do this a number of times (e.g. 5 times ) to ensure the gun is refilling correctly each time. Check the amount of product that is dispensed. If the gun has dispensed the correct amount then you are able to proceed with dosing, confident that the equipment will deliver the correct amount of product required.

If the dosing gun is not delivering the required amount try to adjust settings and repeat the test until you’re satisfied it is delivering the correct amount. If the gun is not refilling correctly it may be indicative of a problem with seals or other components, you will need to replace it on this occasion with an alternative one and check that it is working correctly. Some dosing guns manufacture’s supply repair kits that allow you to replace seals and other components which could resolve this issue. Always check tubing and lids are sealed tight – some container lids that do not contain breathers may need to be released periodically during dosing to reduce vacuum in the dosing pack.

Remember when you finish dosing it’s important to ensure the dosing gun is cleaned fully to remove any residue of the product that was used this will also help to prevent damage to seals and other components.