EC-AH-011v1 January 2018 Page 1 of 5 Standard Operating Procedure Equine Center Clemson University SOP ID: EC-AH-011v1 January 2018 Title: Injection Techniques Author(s): Julia Tagher, CU Equine Center Manager Approval Signatures: Julia Tagher, CU Equine Center Manager / Date John Parrish, DVM, University Veterinarian / Date Disclaimer: This SOP has been prepared and approved for sole use by the Clemson University Equine Center and may not be applicable to other facilities. Changes to this SOP require approval by the University Veterinarian. Reviewer Signature Date
EC-AH-011v1 January 2018 Page 2 of 5 Injection Techniques All medications or vaccines will be administered according to label dosage and route unless otherwise directed by a veterinarian. The first step to administering an injection is to choose the proper needle and syringe size. Typically, injections are given to horses with a 20g x 1.5 inch needle for intramuscular and subcutaneous injections or a 16-18g 1.5in needle for intravenous injections. The syringe chosen should be larger than the volume of substance being administered. For example, if the dose is 2ml, a 3ml or larger syringe should be chosen for the administration. This will allow for proper measurement and injecting without requiring the plunger to be pushed from the further most position. Attach the needle and load the syringe with the amount of drug/vaccine. Usually this can be accomplished by inserting the needle in the rubber stopper on top of the vial and pulling back on the syringe plunger. Pull the needle and syringe from the rubber stopper when the desired dose is reached. Remove any air bubbles from the syringe by holding the syringe upright and gently tapping the barrel on the edge of a hard surface or quickly thumping. When the bubble is at the top of the syringe, gently push the plunger until the air is removed. Recheck the dose after air bubbles are removed. Once your needle and syringe are loaded and ready, choose an injection site. The preferred injection site is the triangle of muscle at the base of the neck in front of the scapula (see illustration below). Ideal Injection Site Alternative sites include the hind quarters, shoulder, thigh or chest areas, but the above site is preferred.
EC-AH-011v1 January 2018 Page 3 of 5 Intramuscular (IM): For an IM injection, firmly pinch the horse's skin next to the injection site for a few seconds prior to inserting the needle. While holding the pinched skin, insert the needle next to the pinched area perpendicular to the skin and deep into the muscle. Pull back on the plunger (aspirate) and watch for blood returning into the hub or syringe. If blood is seen, remove the needle, discard the syringe, and begin again. If no blood is seen, push the plunger in and inject the contents of the syringe. Remove the needle and discard in a sharps container. Another method is to hold the needle between the thumb and forefinger. Tap the horse vigorously 2 to 3 times with the side of your palm in the injection site and without breaking your rhythm, rotate your hand and insert the needle. However, some horses may learn to associate the taps with the following needle stick and react prior to the injection. A similar method is rubbing against the direction of horse's hair growth several times while holding the needle between the thumb and forefinger. Insert the needle on the last rub. Subcutaneous (SQ or SC): For a SQ injection, pinch the horse s skin to form a tent. Insert the needle at an angle into the tent until it sits in the area under the skin. Aspirate and inject the content of the syringe if no blood is returned on aspiration.
EC-AH-011v1 January 2018 Page 4 of 5 All injection sites will be monitored for three days after any injection for any signs of abscess or irritation. If an abscess develops, the University Veterinarian will be consulted for further treatment. It is common for a small nodule to be felt for several days after a vaccination, but the area should not be warm to the touch or painful for the horse. If any abnormalities are noted after an injection, inform farm management immediately. Intravenous Injections (IV): Intravenous injections should only be administered at the direction of a veterinarian or in adherence to standard operating procedures (SOP s). The administration of medications by intravenous injection is an efficient way of achieving quick blood concentrations of the prescribed drug. However, if the injection is made inappropriately and is injected intra-arterially, a neurological crisis could occur. Depending on the drug and the amount, a horse may convulse or collapse if it receives an injection intro-arterially. This reaction could be fatal. The anatomical reason for this rare occurrence is that in horses the carotid artery lies in close proximity, just medial to the jugular vein. In some horses, the carotid pulse is more easily palpated. These horses may be more prone to inadvertent arterial injection. However, to minimize the probability of inappropriate administration, all injections should be made with caution. The injection site is located in the jugular furrow of the horse s neck. If the site is visibly contaminated with mud or manure, clean the area thoroughly, but delicately with antibacterial soap and water. Dry the site prior to injection. If the horse s hair is extremely long, clipping may be necessary as long as it doesn t excite the horse. Injection Site Prior to insertion of the needle, ensure the horse is restrained properly. Some horses are very reactive and an accomplished horseman can anticipate most problem animals. A combination of simple techniques should prove helpful in restraint hand twitch, twitch
EC-AH-011v1 January 2018 Page 5 of 5 application, skin pinch, covering the horse s eye on the side of the venipuncture, horse lead shank application, etc. Restraint should be no more severe than necessary to get the procedure accomplished safely. To perform the injection, first occlude the jugular vein with finger pressure proximal to the estimated injection site. This will cause the vein to fill with blood and distend. The vein should be palpable and, in most cases, visualized. With a quick, firm motion insert the needle into the vein at a 45 angle. INSERTION OF THE NEEDLE SHOULD BE TO THE HUB AND DIRECTED DOWN THE VEIN. This helps stabilize the needle making it less likely to advance unexpectedly into the artery that lies underneath. Insertion of the needle should be quick with the least amount of extraneous movement. Practice of this technique will be necessary for the operator to achieve competency. Upon insertion and the appearance of blood in the needle, it must be discerned if the needle is in the artery or the vein. By occluding the vein proximal to the insertion point of the needle, if venous in nature, the blood flow will increase. If arterial in nature, blood flow will cease upon application of pressure proximal to the insertion point. Upon release of occlusion, the blood may be seen to spurt in a pulsatile rhythm if arterial. If arterial blood is detected, the needle should be withdrawn, and venipuncture attempted proximal to the initial site. After satisfactory placement of the needle is assured, attach the prepared syringe. A slight pull back on the plunger will allow visualization of blood in the hub of the syringe and can help assure placement is accurate during injection of the medication. If at any time during the injection the horse moves possibly causing the needle to be misdirected, the syringe should be detached from the needle and the jugular occlusions test should be repeated. If unacceptable or unclear results occur, replace the needle with a new needle and perform the procedure at a new site. After injection of the medication, withdraw the needle and dispose of it properly in a sharps container. The neck should be observed over the next few days for swelling. Veterinary advice should be sought immediately upon the observation of any abnormal signs. Some medication is very irritating if injected outside the vein, so it is especially important that records are kept detailing medications administered and in what location. By following these simple guidelines, safe intravenous injections can be administered.