In my last post I wrote about coming home from vacation to find my horse needed IM injections for two weeks. I had never given one, but I figured now was an excellent time to learn how. It’s impractical (and would be cost prohibitive) to ask your vet to come twice a day. So, I called a friend who told me, “it’s easy.” Then I went onto the Internet and found this illustrated guide. Here is another good resource.

Giving an IM shot proved to be relatively simple:

• Clean the area with alcohol (some sites say this isn’t necessary, but I don’t think it can hurt)
• Insert the needle deep into the muscle
• Attach the syringe
• Aspirate (pull back on the plunger to make sure you are in the muscle, not in a vein). Some medications can be harmful if incorrectly injected.
• Inject the medication slowly.
• Watch your horse for an adverse reaction.
• Dispose of the used needle and syringe properly.

But it’s always something. When I returned from vacation, The woman giving Kroni his injections had given them all in his neck. After several days of 2x/day shots, his neck was so sore that he would no longer stretch down and eat his grain from his feed dish. I immediately started him on bute and learned to find alternative injections sites: I found that rotating left neck, left buttock, right neck, right buttock worked very well. I did not try the pectoral muscles as it just looked more complicated.

My horse is very tolerant of being stuck with a needle, so I did not need to distract him. If your horse is needle shy, you can distract him by pinching the skin and inserting the needle next to the pinched area or tapping the horse several times and then inserting the needle instead of a tap. I’ve always thought that would be a sure way of alerting your horse to an imminent injection, so that might work better with the occasional stick rather than the heavy duty, several times per day routine.

While adverse reactions are infrequent, there are some risks to performing IM injections. These include:

Dependent Oedema – a mild, cool swelling that can occur after IM injection into the chest muscles. It normally will resolve itself over time, but if the swollen area is warm, the horse seems to be in pain or is lethargic, it’s a good idea to call your vet.

Abscesses and Bacterial Infections are associated with certain medications. The most common one is flunixin meglumine (Finadyne®). One of the most serious side effects of an intramuscular injection of this drug can be a bacterial infection involving Clostridium spp. This is a severe infection that requires veterinary care. Banamine is also associated with bad reactions when delivered through IM injection, and it is recommended that you do not inject it.

Procaine Reaction – occurs as a reaction to procaine penicillin when the procaine gains access to the circulatory system and causes intense constriction of the blood vessels in the brain. It is very important that when you give this medication that it is not injected into a vein. If this reaction occurs, it manifests itself in ways that vary from muscle twitching to kicking, pawing, seizures, and even sudden death.