As long as a horse isn’t needle shy, its handler should always be present to hold it if it reacts negatively to an injection. A tied horse trying to kick during this procedure may pull back against their lead rope and injure itself during its attempt.
Injection sites should be large enough to avoid hitting bone, blood vessels or ligaments. An ideal injection site would be located within an actively used muscle mass on your horse.
Find the Vein
Like any procedure involving puncturing the skin of a horse, injecting insulin requires taking some risks. To help mitigate them, the best course is to consult an experienced friend who can demonstrate proper injection technique before undertaking this yourself. Alternatively, seek help from your veterinarian who may also demonstrate proper injection technique.
When administering injections at home, injecting via the fetlock or needle in the jugular vein is generally the safest and most reliable approach. Access to this area will give you confidence that you can administer injections correctly.
However, this area can be challenging to locate and can be quite painful for horses. To minimise discomfort for both parties involved in injection, an ideal site would be found within a triangular muscle mass in the base of the neck; specifically including nuchal ligaments along the crest, cervical vertebrae that form an S-shape between ears towards shoulder point, scapula (shoulder blade), nuchal ligaments along crest of neck, cervical vertebrae that form backward S curve between ears toward shoulder point and scapula (shoulder blade). This provides large muscle mass which reduces likelihood of muscle soreness after injection while being relatively safe for injectors who can bury needle all the way into its hub without hitting bones, nerves or blood vessels.
Locate this injection site by placing your palm against the front shoulder and just below the poll, about one third up from where the neck slopes to where it slopes towards the top chest. Pinch this area of skin until it holds firm – that will be your injection site!
Draw Back on the Needle
Injecting medications improperly can have severe repercussions, from infections at the injection site to life-threatening reactions to drugs. Therefore, it’s vitally important that you follow all directions from your veterinarian and use clean and sterile needle and syringe equipment. If this is your first time giving an injection, having someone experienced show you the proper technique may also prove invaluable as a supervisor during any initial attempts at self-administration.
Before injecting, wet the area with alcohol to make locating and identifying veins easier. Avoid “tapping” your horse’s neck at the injection site as this may be painful and alert him or her of something happening; an ideal location would be near the base of his/her head triangle for injections.
To locate a jugular vein on your horse, raise its head and feel for it in its jugular furrow. Jugular veins tend to be shallower than other blood vessels, making it easy to detect with your fingers.
If you find it difficult to locate your jugular vein, an alternative method of injection could be injecting into the hip or gluteal muscles instead. Unfortunately, due to being large muscle groups this method could result in an abscess, which would be difficult and time consuming to treat if medication leaked out during its administration.
Inject the Medication
Once you have identified an ideal injection site, dampen it with alcohol to lessen the chance of your horse reacting negatively to needle insertion, while simultaneously cleaning and disinfecting the area to decrease any risk of infection. As an extra precautionary step it would also be wise to have some emergency epinephrine on hand should there be an adverse reaction before disposing of both needle and syringe afterwards.
The neck is an ideal injection site because it’s easily located and allows the injector to stand safely in an undisrupted environment. When choosing an injection site with large muscle mass, pain associated with needle insertion should be reduced while drug absorption into bloodstream increases significantly. Furthermore, any injection site selected must allow needles up to the hub without hitting nerves, blood vessels or ligaments.
Once the location has been chosen, pinch the skin tightly with one hand while slowly inserting the needle at right angles to the skin into muscle at an appropriate depth. If blood appears at the hub or syringe aspirates into syringe, pull out and redirect to another site immediately – certain medications can kill if accidentally administered into blood vessels, so proper injection is of utmost importance.
Check for Blood
Some people opt to “tap” the injection site of their horse with the heel of their hand prior to inserting the needle, as this irritates and potentially reacts with medication being given. Tapping also alerts horses that something is about to happen and increases nervousness and anxiety levels in them.
Before every injection, pull back slightly on the syringe plunger to see if blood enters the needle hub (which protrudes through the skin). This step ensures that you inject into muscle and not blood vessels – many medications can be dangerous if they get into blood vessels, even leading to death in extreme cases.
Armentrout suggests the best place for injection is the large muscle mass that forms haunches. To find it, place your hand against your neck to feel for the triangle formed by the nuchal ligament along its crest and cervical vertebrae winding their way across its top; when your palm rests upon this triangle it serves as the injection site.
Some horses can be fearful of needles and need the presence of an experienced handler to keep them safe during an injection procedure. A handler can especially be beneficial when working with horses who aren’t yet halter trained as this could allow for faster injection times without panicked responses from their rider or kickback from being injections.