There are many reasons why a veterinarian or horse owner would want to check a horse’s pulse or heart rate. Obviously, these reasons include checking for illness in the animal however, a pulse can also be used to determine if a horse is improving from illness or injury or for pre-purchase exams. At this time of year when the grass is starting to come in so nicely, knowing how to check for a digital pulse may also help you prevent laminitis in your horses (managed time on pasture is additionally paramount and a completely different topic not touched upon in this article.)
But let\’s get back to the subject. There are several places on the body where a person can take a horse’s pulse and one of the most frequently checked is the digital pulse. Once you are familiar with the feel of a normal digital pulse, understanding what a “bounding” digital pulse feels like is an excellent horse husbandry skill to possess. An increased digital pulse means that the heart is pumping arterial blood into the enclosed hoof capsule, which has increased pressure and resistance to the flow of blood through the foot. This happens due to inflammation in the bone and soft tissue (ligaments, digital cushion, etc.) of the hoof capsule. An increased digital pulse is often a tell-tale sign of laminitis.
While all horses have a digital pulse, sometimes it can be difficult to find as it is taken on the posterior (palmar) digital artery on the pastern between the coronary band and fetlock. In this article, Dr. Dennis Rach of Moore Equine Center near Balzac, Alberta explains step-by-step how to locate the digital pulse.
#1 – The tough fibrous tissues that can be found at the back of a horse’s legs are called the superficial and deep digital flexor tendons. They are responsible for flexing the joints of the horse’s lower leg, they precent the fetlock from overextending and they help with weight bearing. Using your thumb, locate the flexor tendons at the back of the leg.
#2 – Locate the suspensory ligament. The suspensory ligament originates below the bottom row of the knee bones between the splint bones and extends down to the fetlock. It divides into two just above the fetlock and each branch joins to a sesamoid bone, blending with a common digital extensor tendon. Its job is to support and prevent over extension of the fetlock joint.
#3 – Locate the cannon bone. The weight bearing bone of the lower leg that stretches from the knee joint to the fetlock joint.
#4 – Follow the suspensory ligament down. Again using your thumb, follow the suspensory ligament all the way down until you find the middle, or most convex point of the fetlock joint.
#5 – Destination: Digital Pulse. From the middle of the fetlock, feel your way one finger-width back to find the digital arterial pulse.
A digital pulse can be hard to find in horses that are resting or cold. Once you can familiarize yourself with finding and feeling a normal digital pulse, it will be easy to determine the difference between a bounding pulse. In an increased digital pulse, you can feel the blood pump harder against your thumb and fingers.