How To Give a Horse a Shot

When it comes to knowing how to give a horse a shot, there are definitely some do’s and don’ts you want to follow. We’ll help you feel prepared and confident when the time comes to give your horse an injection.

Why You Should Know How To Give a Horse a Shot

As a horse owner, you likely recognize the importance of knowing how to care for a wound or pull a twisted shoe. But are you prepared to jump into action if your vet tells you over the phone to administer an injectable medicine? Do you know if a specific drug should be administered intravenously (IV) or intramuscularly (IM)?

Common medications and vaccines you may find yourself administering to your horse with a needle and syringe include:

• Phenylbutazone (bute): A non-steroidal anti-inflammatory drug (NSAID), Bute reduces pain and inflammation and is commonly used for musculoskeletal injuries. When injected, bute should be given IV, never IM.

• Flunixin meglumine (Banamine): Also an NSAID, Banamine is usually used to control pain and inflammation in colic cases and eye injuries. When injected, bute and Banamine MUST be given IV, never IM.

• Acepromazine: A tranquilizer commonly called “ace.” Ace can be given IV or IM, and is usually given in preparation for a medical procedure.

• Vaccines: When injected, vaccines are always given IM, never IV. Legally, a rabies vaccine must be administered by a veterinarian, but other routine vaccines can be given by an educated horse owner.

How To Prepare a Horse Injection

For this part, you will need an injectable bottle of medication, a syringe, such as the Terumo Luerlock Equine Syringes, and two needles, like the Dynarex Hypodermic Thin Wall 20 Gauge Needles.

Before you draw the medication from the bottle, see if it requires special handling. For example, all vaccines should be stored refrigerated until ready to use, and bute is a photosensitive drug, meaning that it’s damaged by light and must stay in its opaque-colored bottle until administration.

To draw up an injectable medication, use a new sterile syringe and hypodermic needle every time.

1. Choose a Syringe

Choose a syringe size appropriate for the volume of medication you need; these range from 1cc to 60cc. One cc, or cubic centimeter, is the same amount of liquid as one milliliter (ml).

2. Choose a Needle

The length and gauge (width) of the needle you choose to draw up medication do not matter as much as the specifics of the needle you use to give a horse a shot.

3. Assemble the Shot

Once you’ve selected an appropriate syringe and needle combination, assemble the two. Syringes either have a screw-on (luer-lock) or slip-on (luer-slip) mechanism to attach the base of the needle to the syringe.

4. Take Off the Needle Cap

Do not take off the needle cap until after the syringe and needle are connected and your injectable bottle is nearby. If the bottle has previously been opened, it’s always a good idea to wipe its rubber seal with an alcohol-soaked gauze pad.

5. Draw the Medication or Vaccine

Turn the bottle upside down and insert the needle through the bottle’s rubber seal. Pull back on the syringe’s plunger. The medication will flow into your syringe. Keep going until you reach your desired dosage based on the measurements (in ml) printed on the outside of the syringe.

Pull out the needle and remove any air bubbles by holding the syringe so the needle points up. Tap the barrel a few times to move the air bubble to the top, and slide the plunger enough to push the air out before you give the shot. Once the correct dosage is set with no air bubbles, put the cap back on the needle.

6. Swap the Needle

Swap the needle out for a new 19–22 gauge, 1- to 1.5-inch-long needle. Swapping needles ensures you “poke” your horse with a sharp needle that will penetrate the tissue smoothly and won’t snag on the skin (ouch!).

How To Give a Horse a Shot

You’ve got your injection drawn up with a fresh needle atop your syringe. When it’s time to actually give the horse a shot, safety is key. Just like people, some horses are afraid of this procedure. Have a competent holder hold them with a lead rope and halter, and position yourselves in the horse’s stall near the door for quick escape, just in case you need to move out of the stall for safety.

The techniques for administering an IM versus IV shot differ:

Intramuscular (IM) Injections in Horses

IM injections in horses are easier and carry fewer potential risks than IV injections in horses.

Where to Give an IM Injection in Horses

The area of a horse’s anatomy to give a horse an IM shot is the big muscle in the middle of their neck. The borders of this muscle include:

• Scapula (front edge of a horse’s shoulder)

• Nuchal ligament, which runs at the top of the neck near the mane

• Cervical vertebrae that run along the bottom of the neck

The pectorals and hamstring muscles are also considered safe, but the gluteal muscles at the top of your horse’s rump are not. That’s because, in the unfortunate event that a horse develops an abscess following an IM injection, you won’t have gravity helping you drain that abscess, and the pus will pool and stagnate.

Pectoral muscles are located in the lower chest. Do not stand in front of the horse but off to the side if you choose to administer the horse shot in this location, in case your horse strikes out.

Hamstring muscles are large muscles located below the point of the buttocks. You should stand off to the side when using this site in case your horse decides to kick.

How To Give a Horse an IM Injection

IM injections in horses should always be given with a 1.5-inch, 20-gauge needle (to get deep in the muscle belly).

1. After removing the cap, insert the needle all the way into the hub at a 90-degree (perpendicular) angle.

2. Once the needle is in, and before you push the plunger, aspirate. Aspirating means pulling back on the plunger to make sure that you get negative pressure (air), not blood. If you see blood swirl into your syringe, you’ve accidentally hit a blood vessel. No harm done—simply pull out, get a new needle, and try again.

3. If there is no blood, your syringe will give a small amount of resistance to being pulled back. This is a good thing! Now you may inject the substance by pushing down on the plunger.

4. Pull out the needle slowly in the opposite direction of how you put it in.

Intravenous (IV) Injections in Horses

Some medications cannot be injected into the muscle—ever. Banamine is a prime example.

Giving Banamine IM can have a devastating, life-threatening consequence: a bacterial infection called clostridial myositis that will cause the muscles to slough off. Banamine is always an IV injection in horses.

This being said, if you’re not comfortable with IV horse injections, the same injectable solution can also be administered orally, by squirting it under the horse’s tongue. Safety first!

An IV injection can be fatal if you accidentally inject any substance into the carotid artery located just beneath the jugular vein. For this reason, IV horse injections should be taken seriously, and you should not attempt one until your veterinarian has validated your ability to safely execute them.

Where to Give an IV Injection in Horses

Find the jugular groove, which lies on the lower side of the horse’s neck, and hold off with your non-dominant hand to cause the vein to increase pressure and distend so you can see it. In a normal horse the vein is collapsed or not visible until you hold it off.

How To Give a Horse an IV Injection

It is recommended to use a 1-inch, 20-gauge needle for IV injections. The 1-inch needle keeps you at less risk of hitting the carotid artery.

1. Push your needle in all the way, at a 45-degree angle from the skin.

2. Once you believe that the needle is inside the vein, pull back, just as you would with an IM shot. Here, however, you do want to see blood fill your syringe. Dark blood is good. Bright red blood can indicate that you are in the carotid artery. Negative pressure means you’re not in a blood vessel at all. If that’s the case, redirect, and pull back again before injecting.

3. If you see dark blood, you are safe to inject the medication (and drawn blood) into the horse by pushing down on the plunger. If you are concerned you are no longer in the vein, simply stop injecting the medication and draw back on the plunger as blood should fill the syringe.
   
   If no blood fills the syringe, then you are no longer in the vein and you should redirect your needle or pull out and start over with a new needle. NOTE: Banamine is extremely irritating to a horse’s soft tissue, and you do not want to get any of the Banamine injected outside of the jugular vein. When in doubt, always check that you are still in the vein.

4. Pull out the needle slowly in the opposite direction of how you put it in.

IMPORTANT: After any injection, put the cap back on the needle and dispose of the syringe and needle in a designated sharps container. Needles and blood-contaminated products cannot be thrown into the regular trash.

Always ask your primary veterinarian before giving any medications. If you are not comfortable with giving medications IV, both Banamine and bute come in oral formulations in paste, powder, or pills.