Marilyn - Owner of minis for nearly 20 years
Miniature Horse Farms Directory Site Admin
Horses and the Anguish of Laminitis
Understanding laminitis and the misery it causes a horse is essential for all owners, whether their horses are used for sport, for pleasure, or for work. Here are some basic facts about laminitis, also called founder. Layers of soft, highly sensitive tissue called laminae attach the coffin bone, which forms the center of the foot, to the hoof wall. Laminitis occurs when the laminae are inflamed. Toxins in the horse's bloodstream affect the blood flow to the hoof. The inflammation occurs in a closed space that cannot expand to allow for swelling as skin does, for example. Thus the blood vessels constrict and the blood flow decreases. In the worst cases, where the inflammation is left untreated, the laminae may detach, causing the coffin bone to move down. (This downward movement is probably where the term "founder" comes from. In Middle English, upon which our present-day language is based, the term foundren meant to sink to the ground.) Now the horse's sole is flat rather than the normal concave shape, or it may become convex and press on the ground. All of this causes the horse excruciating pain. Writing in Mother Earth News, Jon Geller, D.V.M., says, "Imagine having all of your fingernails and toenails peeled off simultaneously and you can appreciate the degree of pain involved in laminitis." There is no sadder sight than a horse standing in the classic founder stance. When the pain is in his front feet, the horse will try to place those feet forward, in front of his body, and his back feet forward, under his body in an attempt to get some relief. What brings on laminitis in the first place? If a horse is allowed to eat too much rich grain or grass, the bacteria in his intestines will be affected unfavorably. Bacterial poison will enter his bloodstream and cause laminitis. A horse owner should worry about laminitis if anything initiates the release of toxins into the bloodstream, such as colic or an infection in the uterus, for example.
Other causes may be allowing the horse to drink too much cold water or overworking him on a hard surface, thus inflicting concussive injuries to his hooves. Black walnut shavings as bedding and beet tops as feed are also culprits. Other factors include diarrhea, fever, carrying too much weight on one leg because the horse is lame, insulin problems in overweight horses, Cushing's disease (a small, benign tumor in the pituitary gland) in older horses, and a long application of steroids.
Owners and vets may suspect laminitis when they observe the horse shifting his weight back and forth to escape the pain in his feet. The horse may also have trouble getting up and down; he will lie flat to reduce the pain of movement for periods of time that are uncharacteristically long. When a vet tests for laminitis, he or she will look for a rise in pulse and temperature. Veterinarian Jon Geller explains that "A throbbing, pounding pulse can be detected in the arteries leading to the hooves. The vessels running to the hooves are paired, one toward the inside and one toward the outside of each foot; you can easily feel the pulse by placing your index finger on the back of the leg, just above the top of the hoof. If a horse is in pain, its pulse will often increase to greater than 50 beats per minute . . . . You will occasionally feel heat at the top of the hoof in an area known as the coronary band. When hoof testers are placed on the hoof, there is a consistent pain response everywhere on the sole. In addition, you will sometimes see a separation of the inside hoof from the sole of the foot, a condition commonly known as 'seedy toe.' X-rays of the foot may show rotation of the last toe bone. . . A final way to check for laminitis is to . . . inject the horse with a local anesthetic to deaden the nerve going to the sole of the foot. If the lameness goes away, it's a good indication of laminitis, especially if the pain and lameness return after the local anesthetic wears off."
Veterinarians say that a mild case of laminitis can often be treated with good results. If a horse has eaten too much, for example, Dr. Geller advises that "Cases of laminitis caused by grain overload can often be headed off by treating the horse with a mineral oil drench. A flexible plastic tube is threaded through the horse's nose into the stomach . . . and a gallon of mineral oil is poured down a funnel, where it hastens along the contents of the stomach and intestines before they can be absorbed. The stomach can also sometimes be emptied by putting several liters of water down the tube and siphoning off its contents."
Depending on the extent of individual cases, vets might suggest appropriate remedies such as changing the horse's lifestyle, using medication such as cortisone or antihistamines to reduce the swelling, and bringing in a farrier to do therapeutic shoeing.
But in an advanced case, where the horse's hoof has been inflamed a long time, the sole is flat or convex because the coffin bone has rotated too much, bone might have punctured the sole, there are deep ridges around the hoof, and the horse is in terrible pain, the horse is fatally crippled. Then the owner must decide if the horse should be put down.
For more on laminitis, go tohttp://www.motherearthnews.com (search the archive for Jon Geller) and http://www.equinepodiatrycenter.com/laminitis.
About the Author
Marilyn M. Fisher's first novel is The Case of the Three Dead Horses, a mystery set in Central Virginia where she was a college English professor and administrator. Now living in Tennessee, she continues to write both fiction and prose. Her horse protection web site address is http://www.mmfisher.com.