Laminitis is one of the most crippling of horse diseases, and can even be life-threatening. While prevention is the best method of attack, the effects of laminitis can be diminished if the disease is caught early and treated.
First of all, what is laminitis? Laminitis is pain and inflammation of the laminae of the foot, thought the be the result of toxins in the bloodstream. The toxins can come from the digestive tract, respiratory tract, sinuses, kidneys, liver, or the reproductive tract in mares. Its not certain whether the toxins themselves damage the laminae, or whether result in chemicals like chemokines and histamine that damage the laminae. Either way, the end result is that small arteries in the foot constrict, damaging the laminae. And damaged laminae result in a weakening of the attachment between the coffin bone and the hoof wall. Laminitis can eventually result in a sometimes life-threatening condition called founder, in which the coffin bone rotates or sinks downward. A horse with founder is often permanently lame and sometimes in so much pain that the best course of action is to put him down.
A horse who has had a bout of laminitis can often be identified by something called a “founder ring” on the hoof. These are white lines that go around the circumference of the hoof. If a horse has more than one ring it’s a good bet that he has a tendency toward chronic laminitis.
The causes of laminitis include excess grain consumption, the ingestion of too much water by an overheated horse, concussion to the feet from hard or fast work on a hard surface, standing on a hard surface for too long, ingesting lush pasture (particularly alfalfa or clover), viral and bacterial infections, colic, surgery, Cushings syndrome, and certain medications. Mares with hormonal difficulties or uterine infections, as well as those who retain part of the afterbirth after foaling, can also be susceptible to laminitis.
How do you tell if your horse has laminitis? Unfortunately, the onset can be pretty quick. The sole, wall, and coronary band of the hoof will be significantly hotter than normal, and the digital artery over the fetlock joint will have a rapid, pounding pulse. A horse may be anxious, shaky, and sweating with increased respiration.
The “founder stance” is another indication that your horse might be suffering from founder. In this stance, your horse will stand so that the affected feet bear as little weight as possible. A horse whose front feet are affected will stand with his back feet up underneath him and the front feet placed forward, with the weight on the heels. A horse with founder in all four feet will most likely lie down and refuse to get up. A hoof tester that shows pain and tenderness on the entire sole will clinch the diagnosis.
If you suspect laminitis in your horse, call your vet immediately! Your vet will treat the horse with a multi-pronged approach designed to reduce inflammation and restore blood circulation to the laminae, diagnose and treat whatever is causing the toxemia, support the coffin bone during the healing phase, and prevent the coffin bones from rotating or sinking. Your vet will also prescribe a certain diet for your horse, which is critical to follow. How long before you’re your horse is sound again? About 90 days, and sometimes even more.
What’s the prognosis for a horse with laminitis? While some horses respond really well to treatment without further complications, others do not. The trick is to catch the laminitis before the laminae are permanently damaged, in which case blood supply won’t be able to be fully restored. Horses with chronic cases of laminitis can be kept somewhat sound with proper trimming, shoeing, and feeding.
