How to drench cattle accurately for effective worm control

Accurate cattle drenching is essential for effective parasite control, maintaining animal health, and preventing drench resistance. To ensure correct dosing, farmers should read the product label carefully, weigh animals accurately, use calibrated equipment, and apply the correct administration technique.

1.  Read the drench product label

Before you drench, take the time to carefully read the label on the product. It contains essential information such as:

• What it’s for: The label will list which parasites the drench targets (e.g. roundworms, lungworm, etc.). If you’re unsure which drench your herd needs, check with your vet.
• How to use it: Check whether the product is an oral, pour-on, or injectable drench, and follow the instructions for that method.
• Dose rate and timing: Always give the correct dose for the animal’s weight and follow the withholding periods for meat and milk.
• Safety and handling: Look for any protective gear you need to wear, warnings about mixing with other products, and steps to prevent reactions or environmental harm.

2.  Weigh cattle before drenching for accurate dosing

To make sure each animal gets the right amount of drench, you need to know their weight. Drench products are designed to be given at a specific dose per kilogram of body weight.

• Use scales whenever possible — this is the most accurate way to weigh cattle before drenching.
• If you don’t have scales, estimate carefully and always dose to the heaviest animal in the group to avoid under-dosing.
• If there’s a big difference in size, split cattle into lighter and heavier groups, and dose each group based on the heaviest animal in it.
• Accurate weighing helps ensure the drench works effectively, prevents parasite resistance, and avoids wasting product.

3.  Use the correct administration technique

Cattle drench can be given in several ways:

• Oral drench
• Pour-on
• Injection
• Controlled-release capsules

The ease of use and effectiveness of each method can vary. Drenching is a skilled job and should not be rushed. Check the manufacturer’s instructions and for more information on correct technique, visit www.wormwise.co.nz

Here are some images showing the correct application for Pour-on and Oral Drench treatments.

4.  Accurate Dosing with the Te Pari Revolution Dosing Gun

UK farmer Crawford Niven uses the Te Pari Revolution Dosing Gun to ensure every animal receives the exact dose for its weight. The Revolution Gun connects wirelessly to the Te Pari Macrostock Scale System, automatically recording each treatment against the animal’s EID tag.

This smart, battery-operated dosing gun:

• Calculates doses automatically for each animal
• Eliminates manual record keeping
• Prevents under- or over-dosing
• Reduces product waste
• Improves treatment accuracy and compliance

Watch the video below to see Crawford treating calves with the Revolution Dosing Gun.

5.  Benefits of an Auto-Calibrating Dosing Gun

Using an automated dosing gun like the Te Pari Revolution offers several key advantages:

• Time saving: No need to calculate doses manually.
• Product savings: No overdosing or dosing to the heaviest animal.
• Improved accuracy: Reduces the risk of drench resistance.
• Automatic record keeping: Track doses, product use, and withholding periods for compliance.

6.  Record Keeping for Drenching Cattle

Keeping accurate treatment records helps track animal health, meet compliance standards, and plan future dosing. Many farms are now required to maintain these records for auditing.

How Macrostock can help with drench record-keeping

Te Pari’s Macrostock Scale system integrates with our Revolution Dosing Guns to automatically calibrate and record treatments given to animals. You can also set up withholding period alerts that will come up on the screen to let you know which animals are still under meat or milk withdrawal periods.

Learn more about the Macrostock Scale System

7.  Maintain your Drenching equipment 

Reliable equipment is essential for consistent dosing.

• Service your dosing guns regularly and keep spares on hand.
• Check for leaks, backflow, and worn parts.
• Inspect nozzles for damage or rough edges.
• Calibrate with drench (not water) before use to ensure correct volume.
• After use, rinse, disassemble, clean with warm water, lubricate moving parts, and reassemble carefully.

8.  Drench Storage, Handling & Expiry dates

To maintain drench effectiveness, you should:

• Store products securely at 4–25°C, away from direct sunlight.
• Check expiry dates and use products within the recommended period once opened.
• Always shake the drum well before filling backpacks to ensure even mixing.

9.  Integrate Drenching into a Parasite Management Plan

Drench use should be part of an internal parasite management plan that includes appropriate policies, planned grazing, good nutrition, monitoring and breeding. We recommend talking to your vet to help you with a parasite management plan to determine when is best to dose cattle and what product is the best option for your herd.

For more information and useful resources, go to: www.wormwise.co.nz