Administering medicine to livestock

Injuries from incorrect medicine administration can cause pain and devalue the carcase, but are preventable. Read our tips on best practice for injections and drenching on farm.

Knowing how to administer drugs may seem simple, but data from the AHDB Beef & Lamb Fallen Stock project found 3.5% of ewe deaths were caused by dosing gun and bolus injuries. These were completely preventable.

In England in 2017, over 1.9% of sheep carcases (176,500) and almost 5.9% of cattle carcases (88,500) contained abscesses. The causes of these abscesses include incorrectly administering subcutaneous and intramuscular injections or using dirty or blunt needles.

Abscesses need to be cut out of the carcase, taking time and reducing meat yield as well as potentially devaluing the primal cuts or whole carcase.

How quickly a medicine starts to work and how long it persists in the animal can be affected if medicines are administered incorrectly.

There can be a risk of allergic reactions through contact with antibiotics so wear gloves or wash your hands after contact.

Remember to shake the container of medicine to mix its contents before use, and to regularly check the settings on your equipment to ensure it is calibrated correctly.

How to calibrate your equipment:

1. Load your equipment with the correct dosage.
2. Empty the dosage into a measuring device, or weigh.
3. Check that the dosage and the amount measured are the same.

How to drench:

1. Restrain the animal’s head in a horizontal position – a slight tilt may improve access, but do not pull the head too far back or too far to one side.
2. Insert the nozzle of the drench gun into the corner of the mouth in the gap between the incisor teeth in front and the molar teeth.
3. Once the nozzle is inside the mouth, position it so it rests just above the back of the tongue – do not jam it in because you can easily damage the back of the throat and cause pain.
4. Make sure that the nozzle doesn’t point directly down the back of the throat. If it’s too deep into the throat, it may prevent the sheep from swallowing.

• Modern syringes and needles are designed to be used only once; however, the same needle may be used for several animals in a short timeframe, but not for more than 10–15 injections
• Only inject into a clean area on the animal
• Use a short needle for subcutaneous injections and a longer one for intramuscular injections
• Never attempt to straighten a bent or burred needle because it is much more likely to break
• The data sheet will state the maximum volume that can be injected at one site – split large volumes into smaller amounts and inject in different locations

Always use the smallest gauge needle for the product and volume to be injected. This will minimise damage to the tissues and reduce leakage of the product from the injection site. For example, for large cattle, a 0.5–1-inch needle for subcutaneous injections, and a 1.5-inch needle for intramuscular injections.

Smaller animals, such as calves and sheep, have a smaller muscle mass, so a shorter needle may be preferable to prevent injury to nerves and other tissues.

Good animal restraint prevents injury to humans and animals. It prevents the needle breaking off at the hub when the animal moves suddenly, prevents accidental self-injection and allows the injection site to be clearly seen.

As part of Red Tractor’s standards, you must have a broken needle policy in your health plan; an example of a broken needle policy can be found on the Red Tractor website.

Good needle practice is a crucial tool to maximise value after slaughter and to minimise risk to consumers.

Subcutaneous injections are administered in areas where the skin is loose, mainly in the neck or behind the shoulder.

How to administer:

1. Grasp a fold of skin and slide the needle through the skin, parallel to the animal’s neck or trunk. This will avoid penetration of underlying muscle.
2. Insert the needle several inches from your hand to avoid accidental self-injection. The plunger of the syringe should always be pulled back after entry, to ensure the needle is not located within a blood vessel.
3. After the injection, briefly massage the site to improve the dispersal of the injected material.

The main site for intramuscular injection is the muscle mass of the neck, for which the animal must be adequately restrained. This ensures no valuable cut of meat is damaged, particularly the hindquarter cuts. The constant movement of the neck ensures good dispersion of the product.

Inserting the needle when connected to the syringe can make it more difficult to insert to the correct depth with a single movement. The syringe hub is the weakest point and will often snap if the animal moves, rendering the contents of the syringe useless and creating potential animal-welfare and meat-safety issues.

How to administer:

1. Make sure the area is clean and dry.
2. Draw up the solution for injection into the syringe.
3. Disconnect the needle and hold the hub firmly between thumb and middle finger. With your fist, ‘thump’ the muscle where the injection will be made – this may help desensitise the area.
4. Insert the needle into the muscle to the hub with a sharp slap action.
5. Connect the syringe to the needle, taking care not to introduce any dirt. Draw back to check there is no blood and then slowly inject the contents of the syringe over 10 seconds. Do not inject too quickly as this may cause the animal pain.
6. After the injection, gently massage the injection site.

If you would like to order a hard copy of Using medicines responsibly, please contact publications@ahdb.org.uk or call 0247 799 0069.