By: Darlene M. Cox
Laminitis is most likely the disease for which veterinarian treatment is most often sought by horse owners of every ilk and discipline. While laminitis is a very painful disease that affects a horse's feet, the exact cause for it may lie in another part of the horse's body or it can be a result of stress. Laminitis is believed by some to only affect the front feet; however, as in the case of Barbaro (TB), winner of the 2006 Kentucky Derby, it compromised his hind feet and ultimately led to the decision of his euthanization. Another notable great who had succumbed to laminitis was Secretariat. Laminitis occurs when blood flow is disrupted to the laminae in the foot, which secures the coffin bone to the hoof wall. The laminae within the hoof becomes inflamed and swollen putting pressure on the coffin bone, shifting it downward, or rotating it, toward the sole of the foot. While it is not completely understood how the damage to the laminae occurs, a number of preceptors have been identified in setting the stage for laminitis. The most prevalent of these is poor digestion, which enables toxins to form and enter the horses's bloodstream. Falling within the poor digestion category are horses that have engorged themselves with grain or lush green grass, which puts their digestive systems in a quandary. Post-partum mares that have retained a portion of placenta will have increased blood toxins that could trigger an acute laminitis episodic event. Diseases such as Cushings or hypothyrodism are two medical conditions that initiate the onset of laminitis. Corticosteroid therapies may generate the development of it, as well. Hoof impact stresses on hard surfaces may spark-off an attack of laminitis. Barbaro was felled by laminitis due to the stress his near-hind foot bore while his badly broken off-side leg was placed in a cast. There are two stages of laminitis: acute and chronic. Recognizing the signs of laminitis and immediately contacting your veterinarian will greatly increase your chances of your horse healing and/or surviving his bout with laminitis. An acute stage is the sudden onset of laminitis. Signs of acute laminitis include the following:
- Lameness in front and/or hind legs. Particularly noticeable when your horse turns in a circle.
- Heat in the hoof
- Increased digital pulse in the feet. (You can find the digital pulse by palpating the inside or outside of the leg toward the back of the mid-pastern or fetlock.) A strong pulse will be indicative of laminitis. If you are unsure what you are feeling for, I suggest you 'practice' finding the digital pulse on a healthy horse. While such a pulse will be very slight, you will know where and how to find it if your horse has a laminitic episode.
- Hesitant walking or the appearance of "walking on eggshells".
- Standing position with front feet stretched out and hind feet well under the horse bearing most of the weight.
- Dished hooves (caused by uneven hoof growth)
- Bruised soles
- Rings in the hoof wall
- Dropped soles/flat feet
- Wide white line (seedy toe)
- Blood pockets and/or abscesses (usually seen with seedy toe)