Livestock injections and what size needle should I choose?

Livestock Injections

Injections play an important role in livestock husbandry, with a range of different products being required throughout an animal’s lifespan. These might include vaccines and antibiotics to vitamins, minerals and medications. Each product comes with specific instructions for administering the injection, so it’s essential to carefully read the packaging each time. Even if you’ve used the same product for a while, instructions may be updated regularly, which could include changes to injection sites or dosage.

There are several methods for administering livestock injections, including:

• Intramuscular (IM): Often administered into the neck or shoulder muscle.
• Subcutaneous (SQ): Delivered into the space just under the skin.
• Intravenous (IV): Injected directly into a vein; this is the most challenging technique and should be done by or under the guidance of a veterinarian.
• Intranasal (IN): Delivered through the nose.

The size of syringes and needles can vary based on the type of livestock, their size, the amount of fluid required, and the injection method. For instance, injections that are more viscous (ie with a thicker consistency) require a larger bore (lower gauge) needle such as a 16-gauge needle commonly used in cattle. Intramuscular injections typically need longer needles (1 to 1.5 inches) than subcutaneous injections (0.5 to 1 inch), as they must penetrate deeper into the muscle.

Always consult your own vet for advice on proper and safe injection techniques for the product you are using.

SUGGESTED NEEDLE SIZES
Animal	Subcutaneous (SQ)	Intramuscular (IM)	Intravenous (IV)
Calf	18 x 3/4″	18 x 1″	18 x 1″
Cow	16 x 1″	16 x 1-1/2″	16 x 1-1/2″
Foal	20 x 3/4″	20 x 1″	18 x 1″
Horse	20 x 1″	20 x 1-1/2″	18 x 1-1/2″
Piglet	20 x 1/2″	20 x 1″	20 x 1-1/2″
Grower/Finisher Pig	18 x 3/4″	18 x 1″	Not recommended
Sow	18 x 1″	18 x 1-1/2″	Not recommended
Sheep	20 x 3/4″	20 x 1″	20 x 1″
Goat	20 x 3/4″	20 x 1″	Not recommended
Dog & Cat	22 x 3/4″	22 x 1″	Not recommended

Please note: The information given here is meant to be helpful and/or educational. It is, in no way, intended to override the diagnosis, treatment or advice of a registered veterinarian.

Other tips for livestock injections:

• The gauge number of needles increases as the diameter gets smaller (meaning an 18-gauge needle is thicker than a 20-gauge needle).
• Avoid mixing injection products, as this can cause tissue damage and reduce the effectiveness of the treatment.
• Always clean the injection site on your livestock to prevent any potential infection, especially from dirt or manure.
• When injecting multiple animals, it’s a good practice to change needles every 10 head or so to prevent bent or blunt needles.
• Use a separate needle to draw up the required dose from the bottle instead of the needle used for injecting your animals.
• If administering multiple injections to the same animal, space them out by a few centimetres or use the opposite side of the neck.