Intramuscular Injections. Small Animal Diagnostic and Treatment Techniques

the dog's head is to your right

Several sites can be used for IM injections in dogs, including the triceps muscle, quadriceps group, dorsal lumbar muscles and the semimembranous and semi- tendinosis muscles. Needle sizes used for IM injections range from 25 to 20 gauge. Muscle is dense tissue and can only accommodate small volumes of fluid (a few ml).

The injection site is swabbed with alcohol to wet down the hair coat to assure IM rather than SQ needle placement. The amount of time the alcohol contacts the skin is inadequate for kill of surface bacteria.

the dog's head to to your right

The triceps muscle belly located caudal to the humerus is one IM injection site. The left thumb is placed on the humerus, isolating the muscle belly in the left hand. The needle is placed in the muscle belly. The plunger is withdrawn to create negative pressure.

If blood is aspirated, the needle should be removed as this indicates needle placement in a blood vessel. Reinsert the needle at a different site. Some pharmacologic substances can cause an anaphylactic reaction if given IV. If no blood is aspirated, the injection is given, the needle is withdrawn and the muscle belly is massaged to facilitate dispersion of the injected material.

the dog's head to to your right

The quadriceps muscle is located anterior to the femur. The left thumb is on the femur. The needle is inserted at a right angle to the muscle belly.

the dog's head to to your right

When administering an injection into the semimembranous/semitendinosis muscle group, the tip of the needle (white arrow) should be directed toward the caudal aspect of the limb so if the patient moves, the needle will not advance toward the sciatic nerve. Notice the left hand is being used to isolate the muscle group caudel to the femur.

the dog's head to to your right

The dorsal lumbar muscles on either side of the midline can be used for IM injections. The thumb of the left hand is on the transverse processes of the lumbar vertebrae.