How do you draw blood from a horse? Where is the best spot, and how do you locate the veins to draw from?

The place that veterinarians always use for blood draws for Coggin’s tests, CBCs, other diagnostic measures, or even to give an intravenous injection is the jugular vein located on either side of the neck. To be more specific, this vein, located in the jugular groove, is on the lower part of the neck just below the muscular area. The jugular vein runs along the whole length of the neck; however, the easiest place to take blood from is about 6 to 8 inches down from the throat latch area. Drawing blood requires a lot of practice, and you should be assisted by a veterinarian prior to attempting it on your own. Tools needed include a needle (18 to 20 gauge is best), needle holder, and a Vacutainer tube (these are the same that are used in humans). Finding the vein can be done by occluding the vein with the thumb of your left hand; then after a few seconds of occlusion, you will see the vein expand just below the skin surface. The vein is about 1/2 to 3/4 of an inch thick. When inserting the needle with your right hand, you must have it at the same angle of the vein prior to insertion. After you are in the horse’s neck, you can insert the Vacutainer tube onto the bottom of the needle, which will rapidly fill with blood if you are in the vein. If you are not in the vein, you might need to redirect the needle to find the right location.
Proper horse handling or restraint is a must when performing these procedures, and again it is always advisable to ask your veterinarian about proper methods before attempting this on your own. Remember that anything contaminated accidentally transferred into the bloodstream could be lethal to your horse.